技术领域Technical field
本发明属于桩基检测技术领域，尤其涉及一种桩顶留置管内拾振检测方法。The invention belongs to the technical field of pile foundation detection, and in particular relates to a vibration pickup detection method in a pile top indwelling pipe.
背景技术Background technique
桩基在房屋、桥梁、铁路、高速公路和桥墩建设中具有广泛应用，作为支撑上部结构的主要受力构件，有必要对既有建筑物下的桩基在长期使用期内的完整性和健康状况进行评估，保证桩基质量，减小安全隐患。Pile foundations are widely used in the construction of houses, bridges, railways, highways and bridge piers. As the main stress-bearing component supporting the superstructure, it is necessary to ensure the integrity and health of pile foundations under existing buildings during their long-term use. Evaluate the condition to ensure the quality of the pile foundation and reduce potential safety hazards.
对于基桩完整性检测，目前工程中广泛使用的是低应变检测技术，其通过各种材质的力锤敲击桩顶，在桩顶施加一个激励使桩身产生振动，并观察桩身质点振动信号曲线判断是否存在缺陷。但是，对于既有建筑物下的桩基而言，由于上部结构尺寸效应的存在，桩身振动情况不可避免地会受到上部结构振动特性的影响，通过低应变检测方法采集到的桩身质点振动信号并不像理想条件下清晰可辨，而是非常杂乱无法辨别桩底反射区，所以传统低应变反射波法检测技术只适用于桩顶自由的测试条件，而无法满足既有建筑物下桩基完整性检测。For foundation pile integrity testing, low-strain testing technology is currently widely used in engineering. It strikes the top of the pile with a force hammer made of various materials, applies an excitation on the top of the pile to cause the pile body to vibrate, and observes the particle vibration of the pile body. The signal curve determines whether there is a defect. However, for pile foundations under existing buildings, due to the size effect of the superstructure, the vibration of the pile body will inevitably be affected by the vibration characteristics of the superstructure. The particle vibration of the pile body collected through the low strain detection method The signal is not as clearly discernible as under ideal conditions, but is very messy and cannot identify the reflection area at the bottom of the pile. Therefore, the traditional low-strain reflection wave detection technology is only suitable for testing conditions where the top of the pile is free, and cannot meet the requirements for piles under existing buildings. Base integrity check.
近年来，旁孔透射波法检测技术也得到了越来越多的关注，其通过在桩身附近的土中竖向钻一检测孔，下放信号接收装置。在桩顶施加激励后，缓慢上提信号接收装置即可提取土中振动信号从而也可以判断桩身完整性。但对于桩身出露地表较多的长桩，考虑到桩身在地面上的长度比较长，有时上部结构振动特性对土振动响应产生的影响也不能忽略。除此以外，运用旁孔测试法涉及到在桩周土里进行钻孔、提吊传感器等操作，工作量往往较大，费事费力，因此采用该法评价桩身完整性的可靠性还有待研究。In recent years, side-hole transmission wave detection technology has also received more and more attention. It drills a detection hole vertically in the soil near the pile body and lowers the signal receiving device. After applying excitation to the top of the pile, slowly lifting the signal receiving device can extract the vibration signal in the soil and judge the integrity of the pile body. However, for long piles with more pile bodies exposed on the ground, considering that the length of the pile body on the ground is relatively long, sometimes the impact of the vibration characteristics of the superstructure on the soil vibration response cannot be ignored. In addition, the use of side hole testing methods involves drilling holes in the soil around the pile, lifting sensors, etc. The workload is often large and time-consuming. Therefore, the reliability of using this method to evaluate the integrity of the pile body remains to be studied. .
此外，对于既有建筑物下的高承台桩基的完整性检测，公开(公告)号为CN112663689B的中国专利提出了一种承台桩基础多测点低应变检测方法，包括以下步骤：沿地表出露部分桩身竖向等间距布置三个速度传感器，用于接收水平或竖直方向桩身速度响应分量；于所有传感器上方桩身施加测试激励；将传感器所采集的速度响应信号进行上、下行波分解，并通过积分变换在频域内构建泛频响函数；通过泛频响函数与虚拟半正弦激励得到剔除复杂上部结构振动特性的虚拟速度响应结果；利用现有基桩振动解析解，通过调整解析解中桩长，对虚拟速度响应结果进行拟合，搜寻最优拟合时的桩长作为预估值，并以此对桩身完整性进行判断。但是，该方法仅适用于高承台桩基础，即检测面需要出露地表或泥面，而对于广泛存在的房屋下的未出露地表的工程桩基并不适用。In addition, for the integrity detection of high cap pile foundations under existing buildings, the Chinese patent with publication (announcement) number CN112663689B proposes a multi-measurement point low strain detection method for cap pile foundations, including the following steps: Three speed sensors are arranged vertically at equal intervals on the exposed part of the pile body to receive the speed response component of the pile body in the horizontal or vertical direction; test excitations are applied to the pile body above all sensors; the speed response signals collected by the sensors are carried up and down. Wave decomposition, and an overtone response function is constructed in the frequency domain through integral transformation; a virtual velocity response result that eliminates the vibration characteristics of the complex superstructure is obtained through the overtone response function and virtual half-sine excitation; the existing analytical solution of foundation pile vibration is used to adjust the For the pile length in the analytical solution, the virtual velocity response results are fitted, and the pile length at the optimal fitting is searched for as an estimated value, and the integrity of the pile body is judged based on this. However, this method is only applicable to high-capacity pile foundations, that is, the detection surface needs to be exposed on the ground surface or mud surface, and is not suitable for engineering pile foundations that are not exposed on the ground surface under the widespread houses.
由此可见，现有桩基检测技术存在以下技术问题：既有建(构)筑物下的服役期间桩基难以进行直接观测和检测，传统低应变反射波法检测技术不再适用；可用于既有建筑物下桩基质量检测旁孔透射波法检测技术需要准备工作较多(提前钻孔、埋管)、现场操作步骤繁琐，检测成本较高且测试结果需要专门技术人员分析；近期提出的可适用于高承台下桩基完整性检测的承台桩基础多测点低应变检测方法对于大量的房屋下工程桩基并不适用。因此，提供一种能够适用于房屋下工程桩基的高效桩基检测技术是本领域技术人员亟待解决的技术问题之一。It can be seen that the existing pile foundation detection technology has the following technical problems: it is difficult to directly observe and detect pile foundations during service under existing buildings (structures), and the traditional low-strain reflection wave detection technology is no longer applicable; The side-hole transmission wave method detection technology for quality inspection of pile foundations under existing buildings requires a lot of preparation work (drilling holes in advance, burying pipes), cumbersome on-site operation steps, high detection costs, and the test results require specialized technical personnel to analyze; recently proposed The multi-measurement point low-strain detection method of cap pile foundations that is suitable for integrity testing of pile foundations under high caps is not suitable for a large number of engineering pile foundations under houses. Therefore, providing an efficient pile foundation detection technology that can be applied to engineering pile foundations under houses is one of the technical problems that those skilled in the art urgently need to solve.
发明内容Contents of the invention
本发明的目的是针对上述存在的技术问题，提供一种桩顶留置管内拾振检测方法,以对房屋下工程桩基进行快速高效的检测，确保桩基安全。The purpose of the present invention is to solve the above-mentioned existing technical problems and provide a method for detecting vibrations in a pile top indwelling pipe, so as to quickly and efficiently detect the pile foundation of the project under the house and ensure the safety of the pile foundation.
有鉴于此，本发明提供一种桩顶留置管内拾振检测方法，包括步骤：In view of this, the present invention provides a method for detecting vibration in a pile top indwelling pipe, which includes the steps:
S1，加速度传感器布置：在位于待测桩基桩顶的留置管内布置若干加速度传感器；S1, acceleration sensor arrangement: arrange several acceleration sensors in the indwelling pipe located on the top of the pile foundation to be tested;
S2，数据采集和预处理：向待测桩基中心上方施加无偏心竖向激励，并通过所述加速度传感器同步采集速度响应时程曲线，之后对速度响应时程曲线进行预处理；S2, data acquisition and preprocessing: Apply non-eccentric vertical excitation above the center of the pile foundation to be measured, and synchronously collect the velocity response time history curve through the acceleration sensor, and then preprocess the velocity response time history curve;
S3，数据处理与分析：将预处理后的速度响应时程曲线输入到轴向多点行波分解法模型中，通过轴向多点行波分解法模型识别传感器下方桩基结构的反射特性，并从反射特性中分析得到桩长和桩身完整性；S3, data processing and analysis: input the preprocessed velocity response time history curve into the axial multi-point traveling wave decomposition method model, and identify the reflection characteristics of the pile foundation structure below the sensor through the axial multi-point traveling wave decomposition method model. And analyze the pile length and pile body integrity from the reflection characteristics;
S4，结果评估和分析：分析轴向多点行波分解法模型输出的数据，根据检测数据进行评估和分析，并采取相应的应对措施。S4. Result evaluation and analysis: Analyze the data output by the axial multi-point traveling wave decomposition method model, conduct evaluation and analysis based on the detection data, and take corresponding countermeasures.
进一步的，所述加速度传感器设置在所述留置管的内表面，所述加速度传感器的安装高度低于承台的下端面，每个留置管中加速度传感器的总量不少于3个。Further, the acceleration sensor is arranged on the inner surface of the indwelling tube, the installation height of the acceleration sensor is lower than the lower end surface of the platform, and the total number of acceleration sensors in each indwelling tube is no less than 3.
进一步的，所述留置管中的各个加速度传感器之间的竖向间隔均匀，且在整个留置管范围内能够实时采集桩身振动信号。Furthermore, the vertical spacing between the acceleration sensors in the indwelling tube is uniform, and the vibration signals of the pile body can be collected in real time within the entire range of the indwelling tube.
进一步的，所述加速度传感器为激振器及振动传感器一体结构式的压电式振动传感器，所述加速度传感器通过固定支架安装在留置管内。Furthermore, the acceleration sensor is a piezoelectric vibration sensor with an integrated structure of an exciter and a vibration sensor. The acceleration sensor is installed in the indwelling tube through a fixed bracket.
进一步的，在所述桩基中预埋所述留置管的方式根据所述桩基的制备方式确定，留置管从承台顶穿过承台进入桩身1m～2m，出露一部分、使管端超过后期承台、达到室内地坪的高度。对于灌注桩，留置管的预埋是在灌注桩基上部承台之前埋管；对于预制桩，留置管的预埋是在桩顶灌芯混凝土之前埋管。Further, the method of pre-embedding the retained pipe in the pile foundation is determined according to the preparation method of the pile foundation. The retained pipe passes from the top of the platform through the platform and enters the pile body for 1m to 2m, with a part exposed, making the pipe The end exceeds the later stage platform and reaches the height of the indoor floor. For cast-in-place piles, the retained pipe is buried before the upper cap of the cast-in-place pile foundation; for prefabricated piles, the retained pipe is buried before the top of the pile is filled with core concrete.
进一步的，相邻加速度传感器的竖向间距为待测桩基的桩身在激励下产生的振动波波速与仪器采样时间间隔乘积的N倍，其中N为不小于1的整数。Further, the vertical spacing between adjacent acceleration sensors is N times the product of the vibration wave speed generated by the pile body of the pile foundation to be measured under excitation and the sampling time interval of the instrument, where N is an integer not less than 1.
进一步的，将每个留置管内的加速度传感器视为一组，当待测桩基中设置了多根留置管时，在每根留置管内均设置一组加速度传感器，根据每组加速度传感器采集的数据均各自得出桩长最优估计值，再取均值作为最终的桩长估计值。Further, the acceleration sensors in each indwelling tube are regarded as a group. When multiple indwelling tubes are set in the pile foundation to be tested, a set of acceleration sensors is set in each indwelling tube. According to the data collected by each set of acceleration sensors, The optimal pile length estimates were obtained separately, and the average value was taken as the final pile length estimate.
进一步的，在所述步骤S2中，施加激励的方式为待测桩中心上方无偏心竖向激励加载方式。Further, in step S2, the excitation method is a non-eccentric vertical excitation loading method above the center of the pile to be tested.
进一步的，在所述步骤S3中，在所述轴向多点行波分解法模型中，进行数据处理与分析的过程包括：Further, in step S3, in the axial multi-point traveling wave decomposition method model, the process of data processing and analysis includes:
S31、确定单位走时Δt为所述加速度传感器中相邻传感器竖向间距与振动波波速的比值；S31. Determine the unit travel time Δt as the ratio of the vertical distance between adjacent sensors in the acceleration sensor and the vibration wave speed;
S32、将上方传感器和下方传感器所采集的速度响应时程曲线分别前移1个单位走时Δt，即朝时间轴负方向移动1个单位走时Δt，然后针对两条移动后的速度响应时程曲线，分别取时间轴上非负部分的信号数据作为处理后时程曲线，并对末尾进行补零使其与原始速度响应时程曲线的数据长度一致，以便于后续求差；其中，按照上下高度，确定所述的若干加速度传感器中位于中间高度的中间传感器，并将位于中间传感器上方的传感器记为上方传感器，对应的，并将位于中间传感器下方的传感器记为下方传感器；S32. Move the speed response time history curves collected by the upper sensor and the lower sensor forward by 1 unit of travel time Δt respectively, that is, move 1 unit of travel time Δt in the negative direction of the time axis, and then focus on the two moved speed response time history curves. , respectively take the non-negative part of the signal data on the time axis as the processed time history curve, and pad zeros at the end to make it consistent with the data length of the original speed response time history curve, so as to facilitate subsequent difference calculation; among them, according to the upper and lower height , determine the middle sensor located at the middle height among the several acceleration sensors, and record the sensor located above the middle sensor as the upper sensor, and correspondingly, record the sensor located below the middle sensor as the lower sensor;
S33、根据信号的传输规律，将处理后曲线与中间传感器所采集的速度响应时程曲线作差，其结果即等效于通过中间传感器位置的上、下行波分别与其前移2个单位走时曲线作差；因此，将上方传感器的处理后时程曲线与中间传感器所采集的速度响应时程曲线作差，得到第一差值曲线，其等效为中间传感器的上行波的差值曲线；将下方传感器的处理后时程曲线与中间传感器所采集的速度响应时程曲线作差，得到第二差值曲线，其等效为中间传感器的下行波的差值曲线；S33. According to the transmission law of the signal, make a difference between the processed curve and the speed response time history curve collected by the middle sensor. The result is equivalent to the upward and downward traveling waves passing through the position of the middle sensor and their travel time curves moved forward by 2 units respectively. Make a difference; therefore, make a difference between the processed time history curve of the upper sensor and the velocity response time history curve collected by the middle sensor to obtain the first difference curve, which is equivalent to the difference curve of the upgoing wave of the middle sensor; The processed time history curve of the lower sensor is compared with the speed response time history curve collected by the middle sensor to obtain a second difference curve, which is equivalent to the difference curve of the downgoing wave of the middle sensor;
S34、对激励位于传感器上方的测试条件而言，在前2个单位走时内，下行波应等于中间传感器时程曲线初段，而上行波由于尚未产生应等于零，由此可以对中间传感器上行波和下行波的差值曲线分别进行还原，得到中间传感器完整的上行波曲线和下行波曲线；S34. For the test conditions where the excitation is located above the sensor, within the first two unit travel times, the downgoing wave should be equal to the initial section of the time history curve of the middle sensor, while the upgoing wave should be equal to zero because it has not yet been generated. From this, the upgoing wave of the middle sensor and The difference curves of the downgoing waves are restored respectively to obtain the complete upgoing wave curve and downgoing wave curve of the intermediate sensor;
S35，针对中间传感器所在位置，将下行波看作输入，上行波看作输出，通过傅里叶积分变换，在频域内将上行波和下行波的傅里叶变换结果之比作为下方桩身的泛频响函数；对泛频响函数施加虚拟半正弦激励，通过将虚拟半正弦激励与泛频响函数在频域内相乘或在时域内卷积，得到剔除上部结构复杂振动特性的虚拟速度响应曲线；根据该虚拟速度响应曲线确定桩底反射时间区间，以及桩长预测范围；S35, for the position of the middle sensor, the downgoing wave is regarded as the input and the upgoing wave is regarded as the output. Through Fourier integral transformation, the ratio of the Fourier transform results of the upgoing wave and the downgoing wave is used as the ratio of the Fourier transform results of the lower pile body in the frequency domain. Over-frequency response function: apply a virtual half-sine excitation to the over-frequency response function, and multiply the virtual half-sine excitation and the over-frequency response function in the frequency domain or convolve in the time domain to obtain a virtual velocity response that eliminates the complex vibration characteristics of the upper structure Curve; determine the pile bottom reflection time interval and pile length prediction range based on the virtual velocity response curve;
S36，获取基桩振动解析解，并通过在前述桩长预测范围内调整解析解中的桩长，得到不同桩长下的理论解速度响应曲线；针对不同桩长下的理论解速度响应曲线，需要通过拟合的方式来确定最佳的桩长，将前述虚拟速度响应曲线和不同桩长下的理论解速度响应曲线经过小波变换，再对两条小波变换后的响应曲线在桩底反射时间区间内的数据段进行拟合，确定使拟合数据均方根误差最小的解析解桩长，并将其作为当前待测桩基的桩长最优估计值，实现对桩身完整性的判断。S36, obtain the analytical solution of foundation pile vibration, and obtain the theoretical solution velocity response curve under different pile lengths by adjusting the pile length in the analytical solution within the aforementioned pile length prediction range; for the theoretical solution velocity response curve under different pile lengths, It is necessary to determine the optimal pile length through fitting. The aforementioned virtual velocity response curve and the theoretical solution velocity response curve under different pile lengths are subjected to wavelet transformation, and then the reflection time of the two wavelet transformed response curves at the bottom of the pile is The data segments within the interval are fitted to determine the analytical solution pile length that minimizes the root mean square error of the fitted data, and this is used as the optimal estimate of the pile length of the current pile foundation to be tested to judge the integrity of the pile body. .
进一步的，在所述步骤S4中，根据轴向多点行波分解法模型输出的数据采取的应对措施包括但不限于桩基缺陷位置修复加固、补桩、加强管道的保养和管理。Further, in step S4, the countermeasures taken based on the data output by the axial multi-point traveling wave decomposition method model include but are not limited to repair and reinforcement of pile foundation defect locations, pile repair, and strengthening pipeline maintenance and management.
进一步的，所述的桩顶留置管内拾振检测方法，还包括步骤：Further, the described method for detecting vibration in the pile top indwelling pipe also includes the steps:
S5，报告输出：根据检测结果生成检测报告，在检测报告中明确桩基的基础信息、检测方法和数据分析结果；影响桩基安全性的异常区域；应采取的措施和建议。S5, report output: generate a test report based on the test results, and clarify the basic information of the pile foundation, test methods and data analysis results in the test report; abnormal areas that affect the safety of the pile foundation; measures and suggestions that should be taken.
本发明的有益效果是：现有的低应变检测技术是在出露地表的桩身上竖向等间距布置若干个加速度传感器，对于已经建成的建筑，由于桩基都在地下，很难在桩身上布置加速度传感器。而本发明可以通过桩顶留置管检测深埋固定在地下的钢筋混凝土桩基内的损伤、缺陷等问题，并且在检测完后可以将加速度传感器取出重复利用，用于解决建筑服役期间对桩基质量的监测问题以及在灾后对建筑桩基损坏程度的评定问题，对于旧房加固、房屋加盖有重要的指导作用。因此，本发明提供的桩顶留置管内拾振检测技术可以有效地解决以上技术问题，提高检测准确性、效率和降低成本，对于确保桩基安全起到积极的促进作用。The beneficial effects of the present invention are: the existing low-strain detection technology is to arrange several acceleration sensors at equal intervals vertically on the piles exposed on the ground. For already-built buildings, since the pile foundations are all underground, it is difficult to install the acceleration sensors on the piles. Arrange the acceleration sensor. The present invention can detect damage, defects and other problems in the reinforced concrete pile foundations fixed deep underground through the pile top retention pipe, and after the detection, the acceleration sensor can be taken out and reused to solve the problem of pile foundation damage during the service of the building. Quality monitoring issues and assessment of the degree of damage to building pile foundations after disasters play an important guiding role in the reinforcement and construction of old houses. Therefore, the vibration pickup detection technology provided by the present invention can effectively solve the above technical problems, improve detection accuracy, efficiency and reduce costs, and play a positive role in ensuring the safety of pile foundations.
附图说明Description of the drawings
图1是本发明所述待测桩基中留置管和加速度传感器的安装位置示意图；Figure 1 is a schematic diagram of the installation position of the indwelling pipe and acceleration sensor in the pile foundation to be tested according to the present invention;
图2是本发明中多根连在一起的待测桩基中留置管和加速度传感器的安装位置示意图；Figure 2 is a schematic diagram of the installation positions of the indwelling pipes and acceleration sensors in multiple pile foundations to be tested that are connected together in the present invention;
图3为本发明所述桩顶留置管内拾振检测方法的实施过程示意图；Figure 3 is a schematic diagram of the implementation process of the vibration pickup detection method in the pile top indwelling pipe according to the present invention;
图4为图3中A区域的局部结构放大示意图；Figure 4 is an enlarged schematic diagram of the partial structure of area A in Figure 3;
图5为本发明中同一待测桩基中安装两根留置管时留置管的位置示意图；Figure 5 is a schematic diagram of the position of the indwelling pipes when two indwelling pipes are installed in the same pile foundation to be tested in the present invention;
图6为本发明中同一待测桩基中安装两根留置管时的立体结构示意图；Figure 6 is a schematic three-dimensional structural diagram when two indwelling pipes are installed in the same pile foundation to be tested in the present invention;
图7为图6中B-B方向的剖面结构示意图；Figure 7 is a schematic cross-sectional structural diagram along the B-B direction in Figure 6;
图8为本发明中同一待测桩基中安装三根留置管时留置管的位置示意图；Figure 8 is a schematic diagram of the position of the indwelling pipes when three indwelling pipes are installed in the same pile foundation to be tested in the present invention;
图9为本发明中同一待测桩基中安装三根留置管时的立体结构示意图；Figure 9 is a schematic three-dimensional structural diagram when three retention pipes are installed in the same pile foundation to be tested in the present invention;
图10为图9中C-C方向的剖面结构示意图；Figure 10 is a schematic cross-sectional structural diagram along the C-C direction in Figure 9;
图11为本发明中同一待测桩基中安装四根留置管时留置管的位置示意图；Figure 11 is a schematic diagram of the position of the indwelling pipes when four indwelling pipes are installed in the same pile foundation to be tested in the present invention;
图12为本发明中同一待测桩基中安装四根留置管时的立体结构示意图；Figure 12 is a schematic three-dimensional structural diagram when four retention pipes are installed in the same pile foundation to be tested in the present invention;
图13为图12中D-D方向的剖面结构示意图。Figure 13 is a schematic cross-sectional structural diagram along the D-D direction in Figure 12.
图中标记表示为：The marks in the figure are expressed as:
1、待测桩基；2、留置管；3、加速度传感器；4、承台；5、测试锤；6信号采集装置；7、充气设备；8、固定支架；9、桩周土。1. Pile foundation to be tested; 2. Indwelling pipe; 3. Acceleration sensor; 4. Cap platform; 5. Test hammer; 6. Signal acquisition device; 7. Inflatable equipment; 8. Fixed bracket; 9. Soil around the pile.
具体实施方式Detailed ways
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请的一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员获得的所有其他实施例，都属于本申请保护的范围。The technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of this application.
在本申请的描述中，需要说明的是，这里所使用的术语仅是为了描述具体实施方式，而非意图限制根据本申请的示例性实施方式。为了便于描述，附图中所示出的各个部分的尺寸并不是按照实际的比例关系绘制的。对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论，但在适当情况下，所述技术、方法和设备应当被视为授权说明书的一部分。在这里示出和讨论的所有示例中，任何具体值应被解释为仅仅是示例性的，而不是作为限制。因此，示例性实施例的其它示例可以具有不同的值。应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步讨论。In the description of the present application, it should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. For convenience of description, the dimensions of various parts shown in the drawings are not drawn according to actual proportional relationships. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered part of the authorized specification. In all examples shown and discussed herein, any specific values are to be construed as illustrative only and not as limiting. Accordingly, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters refer to similar items in the following figures, so that once an item is defined in one figure, it does not need further discussion in subsequent figures.
需要说明的是，本申请的说明书和权利要求书中的术语“第一”、“第二”等是用于区别类似的对象，而不用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便本申请的实施例能够以除了在这里图示或描述的那些以外的顺序实施，且“第一”、“第二”等所区分的对象通常为一类，并不限定对象的个数，例如第一对象可以是一个，也可以是多个。此外，说明书以及权利要求中“和/或”表示所连接对象的至少其中之一，字符“/”，一般表示前后关联对象是一种“或”的关系。It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It is to be understood that the figures so used are interchangeable under appropriate circumstances so that the embodiments of the present application can be practiced in orders other than those illustrated or described herein, and that "first," "second," etc. are distinguished Objects are usually of one type, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and/or" in the description and claims indicates at least one of the connected objects, and the character "/" generally indicates that the related objects are in an "or" relationship.
需要说明的是，在本申请的描述中，术语方位词如“前、后、上、下、左、右”、“横向、竖向、垂直、水平”和“顶、底”等所指示的方位或位置关系通常是基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，在未作相反说明的情况下，这些方位词并不指示和暗示所指的装置或元件必须具有特定的方位或者以特定的方位构造和操作，因此不能理解为对本申请保护范围的限制；方位词“内、外”是指相对于各部件本身的轮廓的内外。It should be noted that in the description of this application, terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" indicate The orientation or positional relationship is generally based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Without explanation to the contrary, these positional words do not indicate or imply the device or device referred to. Components must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be construed as limiting the scope of the present application; the orientation words "inside and outside" refer to the inside and outside relative to the outline of each component itself.
需要说明的是，在本申请中，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者装置不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者装置所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括该要素的过程、方法、物品或者装置中还存在另外的相同要素。此外，需要指出的是，本申请实施方式中的方法和装置的范围不限按示出或讨论的顺序来执行功能，还可包括根据所涉及的功能按基本同时的方式或按相反的顺序来执行功能，例如，可以按不同于所描述的次序来执行所描述的方法，并且还可以添加、省去、或组合各种步骤。另外，参照某些示例所描述的特征可在其他示例中被组合。It should be noted that in this application, the terms "comprising", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements , but also includes other elements not expressly listed or inherent in such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article or apparatus that includes that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved. Functions may be performed, for example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
如图1～13所示，一种桩顶留置管内拾振检测方法，包括步骤：As shown in Figures 1 to 13, a method for detecting vibration in a pile top indwelling pipe includes the following steps:
S1，加速度传感器布置：在位于待测桩基1桩顶的留置管2内布置若干加速度传感器3；S1, acceleration sensor arrangement: arrange several acceleration sensors 3 in the indwelling pipe 2 located on the top of the pile foundation 1 to be tested;
S2，数据采集和预处理：向待测桩基1中心上方施加无偏心竖向激励，并通过所述加速度传感器3同步采集速度响应时程曲线，之后对速度响应时程曲线进行预处理；S2, data collection and preprocessing: Apply non-eccentric vertical excitation to the center of the pile foundation 1 to be tested, and synchronously collect the speed response time history curve through the acceleration sensor 3, and then preprocess the speed response time history curve;
S3，数据处理与分析：将预处理后的速度响应时程曲线输入到轴向多点行波分解法模型中，通过轴向多点行波分解法模型识别传感器下方桩基结构的反射特性，并从反射特性中分析得到桩长和桩身完整性；S3, data processing and analysis: input the preprocessed velocity response time history curve into the axial multi-point traveling wave decomposition method model, and identify the reflection characteristics of the pile foundation structure below the sensor through the axial multi-point traveling wave decomposition method model. And analyze the pile length and pile body integrity from the reflection characteristics;
S4，结果评估和分析：分析轴向多点行波分解法模型输出的数据，根据检测数据进行评估和分析，并采取相应的应对措施。S4. Result evaluation and analysis: Analyze the data output by the axial multi-point traveling wave decomposition method model, conduct evaluation and analysis based on the detection data, and take corresponding countermeasures.
优选的，留置管从承台顶穿过承台进入桩身1m～2m，并出露一部分、使管端超过后期承台、达到室内地坪的高度，在所述桩基中预埋所述留置管的方式根据所述桩基的制备方式确定，对于灌注桩，留置管的预埋是在灌注桩基上部承台之前埋管；对于预制桩，留置管的预埋是在桩顶灌芯混凝土之前埋管。Preferably, the indwelling pipe passes through the cap from the top of the cap and enters the pile body 1m to 2m, and a part of it is exposed, so that the pipe end exceeds the later cap and reaches the height of the indoor floor, and the said pipe is pre-embedded in the pile foundation. The method of retaining the pipe is determined according to the preparation method of the pile foundation. For cast-in-place piles, the retaining pipe is buried before the upper cap of the cast-in-place pile foundation; for prefabricated piles, the retaining pipe is pre-buried at the top of the pile. Pipe buried before concrete.
作为本发明的一些实施例，通常，桩基1根据其制备方式可分为灌注桩和预制桩，其中，灌注式桩基1中留置管2的预埋是在浇灌混凝土前进入桩顶一定深度埋管并出露一部分、使管端略超过后期承台、达到室内地坪的高度；预制式桩基1中留置管2的预埋是在桩顶灌芯混凝土之前埋管，其余管桩和承台连接方式正常施工，预埋的管需要进入桩身一定深度，优选为1m～2m，且需将管底部密封，保证不堵孔、不渗漏。As some embodiments of the present invention, generally, pile foundations 1 can be divided into cast-in-place piles and prefabricated piles according to their preparation methods. Among them, the indwelling pipe 2 in the cast-in-place pile foundation 1 is pre-embedded into the top of the pile to a certain depth before pouring concrete. Bury the pipe and expose part of it so that the pipe end slightly exceeds the later stage cap and reaches the height of the indoor floor; the remaining pipe 2 in the prefabricated pile foundation 1 is buried before the top of the pile is filled with concrete, and the remaining pipe piles and The cap connection method is used for normal construction. The embedded pipe needs to enter the pile body to a certain depth, preferably 1m to 2m, and the bottom of the pipe needs to be sealed to ensure that it does not block holes or leak.
优选的，在所述步骤S1中，所述加速度传感器3为具有高精度、高阻尼比、高灵敏度的加速度传感器。Preferably, in step S1, the acceleration sensor 3 is an acceleration sensor with high precision, high damping ratio, and high sensitivity.
进一步的，所述加速度传感器3设置在所述留置管2的内表面，优选的，所述加速度传感器3的总数量为奇数。Further, the acceleration sensors 3 are arranged on the inner surface of the indwelling tube 2. Preferably, the total number of the acceleration sensors 3 is an odd number.
进一步的，在所述步骤S1中，所述加速度传感器3在所述留置管2中的位置和数量可根据实际需求，如桩基的具体情况和工程要求进行布置，具体以所述留置管2中的加速度传感器3的位置，如竖向间隔、径向间隔均匀，且在整个留置管2范围内能够实时采集桩身振动信号为宜。Further, in step S1, the position and number of the acceleration sensors 3 in the indwelling pipe 2 can be arranged according to actual needs, such as the specific conditions of the pile foundation and engineering requirements. Specifically, the indwelling pipe 2 The acceleration sensors 3 should be positioned at even vertical and radial intervals, and the vibration signals of the pile body can be collected in real time within the entire range of the indwelling pipe 2.
优选的，相邻加速度传感器3的竖向间距为待测桩基1的桩身在激励下产生的振动波波速与仪器采样时间间隔乘积的N倍，其中N为不小于1的整数。Preferably, the vertical spacing between adjacent acceleration sensors 3 is N times the product of the vibration wave speed generated by the pile body of the pile foundation 1 under excitation multiplied by the instrument sampling time interval, where N is an integer not less than 1.
更加优选的，每个留置管2中加速度传感器3的总量不少于3个。More preferably, the total number of acceleration sensors 3 in each indwelling tube 2 is no less than 3.
作为本申请的一些实施例，所述加速度传感器3的安装方式为通过固定支架8固定：即在加速度传感器3上设置固定支架8，通过固定支架8将加速度传感器3送至设定位置后，通过粘贴等方式将所述固定支架8固定在留置管2的内壁上，进而实现将所述加速度传感器3固定在所述留置管2内，其中，所述固定支架8能够传递检测过程中所述加速度传感器所需要接收与检测的信号；所述加速度传感器3与信号采集装置6连接，待测基桩1掩埋在桩周土9中，检测过程中通过测试锤5施加激励，并通过信号采集装置6采集信号，之后对采集到的信号按照本发明所述的方法进行分析处理后得到基桩完整性状况。As some embodiments of the present application, the acceleration sensor 3 is installed by fixing it through a fixing bracket 8: that is, a fixing bracket 8 is provided on the acceleration sensor 3, and after the acceleration sensor 3 is sent to the set position through the fixing bracket 8, The fixing bracket 8 is fixed on the inner wall of the indwelling tube 2 by pasting or other methods, thereby fixing the acceleration sensor 3 in the indwelling tube 2 , wherein the fixing bracket 8 can transmit the acceleration during the detection process. The signal that the sensor needs to receive and detect; the acceleration sensor 3 is connected to the signal acquisition device 6. The foundation pile 1 to be tested is buried in the soil around the pile 9. During the detection process, excitation is applied through the test hammer 5, and the signal acquisition device 6 Collect signals, and then analyze and process the collected signals according to the method of the present invention to obtain the foundation pile integrity status.
作为本申请的一些实施例，所述固定支架8与充气设备7连接，所述充气设备7能够向所述固定支架8中充气，以实现对所述固定支架8尺寸的调整。As some embodiments of the present application, the fixed bracket 8 is connected to an inflatable device 7 , and the inflatable device 7 can inflate the fixed bracket 8 to adjust the size of the fixed bracket 8 .
作为本申请的一些实施例，所述固定支架8可通过机械伸缩杆等送入留置管2内的设定位置。As some embodiments of the present application, the fixed bracket 8 can be sent to a set position in the indwelling tube 2 through a mechanical telescopic rod or the like.
作为本申请的一些实施例，所述固定支架8可通过热熔胶等粘附在留置管2内的设定位置。As some embodiments of the present application, the fixing bracket 8 can be adhered to a set position in the indwelling tube 2 through hot melt glue or the like.
原来低应变只能测桩顶自由的桩完整性，一旦上方做承台再往上做结构，就不能测了。通过本发明所提供的桩顶留置管内拾振检测方法，在桩基服役期间也可以打开桩顶留置管把传感器放进去测，此时虽然桩上方有既有结构，但是通过轴向多点行波分解法可以剔除上部结构的影响，得到中间传感器以下桩身的振动情况，这样可以对桩身完整性进行测试。It turns out that low strain can only measure the pile integrity when the top of the pile is free. Once the cap is built above and the structure is built above, it cannot be measured. Through the method for detecting vibrations in the pile top indwelling tube provided by the present invention, the pile top indwelling tube can also be opened and the sensor placed in the pile top for measurement during the service period of the pile foundation. At this time, although there is an existing structure above the pile, the axial multi-point line can be used to detect vibration. The wave decomposition method can eliminate the influence of the upper structure and obtain the vibration of the pile below the middle sensor, so that the integrity of the pile can be tested.
作为本申请的一些实施例，所述安装于留置管2内表面的加速度传感器3，可以选用激振器及振动传感器一体结构式的压电式振动传感器，通过压电式振动传感器内部的激振器使桩基产生振动，由振动传感器拾取振动信号，由此无需用外部不用在桩身上外加激励而是由其自身直接就能产生一个理想激励。当然，也可以采用普通的加速度传感器，此时可以用外部激励源对桩身施加激励。As some embodiments of this application, the acceleration sensor 3 installed on the inner surface of the indwelling tube 2 can be a piezoelectric vibration sensor with an integrated structure of an exciter and a vibration sensor. The pile foundation is vibrated, and the vibration signal is picked up by the vibration sensor. Therefore, there is no need to use external excitation on the pile body, but it can directly generate an ideal excitation by itself. Of course, an ordinary acceleration sensor can also be used, and in this case, an external excitation source can be used to excite the pile body.
需要注意的是，当相邻加速度传感器3布置的竖向间距小于剪切波或纵波波速乘以采样时间间隔时应适量增大。波速已知时，间距优选取为乘积的整数倍。It should be noted that when the vertical spacing between adjacent acceleration sensors 3 is less than the shear wave or longitudinal wave velocity multiplied by the sampling time interval, it should be appropriately increased. When the wave speed is known, the spacing is preferably taken as an integer multiple of the product.
作为本申请的一些实施例，可如图2所示，对于多根连在一起的基桩，可以在每根基桩里面都放一个留置管，之后对每根基桩各自进行测试。As some embodiments of the present application, as shown in Figure 2, for multiple foundation piles connected together, a retention tube can be placed inside each foundation pile, and then each foundation pile can be tested separately.
作为本申请的另外一些实施例，当同一根待测桩基1中设置了多根留置管2时，可将每个留置管2内的加速度传感器3视为一组，在每根留置管2内均设置一组加速度传感器3，每组加速度传感器3采集的数据均各自得出桩长最优估计值，再取均值作为最终的桩长估计值，以减小结果受测试环境干扰(如温度变化等)产生的误差。优选的，如图5～13所示，可将多根留置管2呈中心对称状设置在同一待测桩基1中，其中，留置管2的数量可根据测桩基1的桩直径d来确定，具体的，当桩直径d≤800mm时，待测桩基1中留置管2的数量应不少于2根；当800mm＜d≤1500mm时，待测桩基1中留置管2的数量应不少于3根；当1500mm＜d时，待测桩基1中留置管2的数量应不少于4根。As other embodiments of the present application, when multiple indwelling tubes 2 are provided in the same pile foundation 1 to be tested, the acceleration sensors 3 in each indwelling tube 2 can be regarded as a group. A set of acceleration sensors 3 are set up inside each set of acceleration sensors 3. The data collected by each set of acceleration sensors 3 respectively obtains the optimal estimate of the pile length, and then the average value is taken as the final estimate of the pile length to reduce the results from being interfered by the test environment (such as temperature). changes, etc.). Preferably, as shown in Figures 5 to 13, multiple indwelling tubes 2 can be centrally symmetrically arranged in the same pile foundation 1 to be tested, where the number of indwelling tubes 2 can be determined according to the pile diameter d of the pile foundation 1 to be measured. Determine, specifically, when the pile diameter d≤800mm, the number of retained pipes 2 in the pile foundation 1 to be tested should be no less than 2; when 800mm<d≤1500mm, the number of retained pipes 2 in the pile foundation 1 to be tested should be There should be no less than 3 pipes; when 1500mm<d, the number of retained pipes 2 in the pile foundation 1 to be tested should be no less than 4 pipes.
作为本申请的一些实施例，当在同一待测桩基1中设置多根留置管2时，留置管2的分布如图5～7所示，当在同一待测桩基1中设置两根留置管2时，两根留置管2呈180°对称分布，两根留置管2分别设置在图5中的A点和B点；当在同一待测桩基1中设置三根留置管2时，如图8～10所示，三根留置管2呈120°对称分布，三根留置管2分别设置在图8中的A点、B点和C点；当在同一待测桩基1中设置四根留置管2时，如图11～13所示，四根留置管2呈90°对称分布，四根留置管2分别设置在图11中的A点、B点、C点和D点。As some embodiments of the present application, when multiple indwelling pipes 2 are set up in the same pile foundation 1 to be tested, the distribution of the indwelling pipes 2 is as shown in Figures 5 to 7. When two indwelling pipes 2 are set up in the same pile foundation 1 to be tested, When indwelling pipe 2, the two indwelling pipes 2 are symmetrically distributed at 180°, and the two indwelling pipes 2 are respectively set at points A and B in Figure 5; when three indwelling pipes 2 are set up in the same pile foundation 1 to be tested, As shown in Figures 8 to 10, the three indwelling pipes 2 are symmetrically distributed at 120°, and are respectively set at point A, point B and point C in Figure 8; when four indwelling pipes 2 are set up in the same pile foundation 1 to be tested, When indwelling the tubes 2, as shown in Figures 11 to 13, the four indwelling tubes 2 are symmetrically distributed at 90°, and the four indwelling tubes 2 are respectively arranged at points A, B, C and D in Figure 11.
作为本申请的另外一些实施例，当在同一待测桩基1中设置两根留置管2时，如图5～7所示，两根留置管2呈180°对称分布，两根留置管2分别设置在图5中的线段OA和OB上，且两根留置管2距离待测桩基1中心点O的距离相等；当在同一待测桩基1中设置三根留置管2时，如图8～10所示，三根留置管2呈120°对称分布，三根留置管2分别设置在图8中的线段OA、OB和OC上，且三根留置管2距离待测桩基1中心点O的距离相等；当在同一待测桩基1中设置四根留置管2时，，如图11～13所示，四根留置管2呈90°对称分布，四根留置管2分别设置在图11中的线段OA、OB、OC和OD上，且四根留置管2距离待测桩基1中心点O的距离相等。As other embodiments of the present application, when two indwelling pipes 2 are installed in the same pile foundation 1 to be tested, as shown in Figures 5 to 7, the two indwelling pipes 2 are symmetrically distributed at 180°. They are respectively set on the line segments OA and OB in Figure 5, and the distance between the two indwelling pipes 2 and the center point O of the pile foundation 1 to be tested is equal; when three indwelling pipes 2 are set in the same pile foundation 1 to be tested, as shown in the figure As shown in 8 to 10, the three indwelling pipes 2 are symmetrically distributed at 120°. The three indwelling pipes 2 are respectively set on the line segments OA, OB and OC in Figure 8, and the three indwelling pipes 2 are located at a distance from the center point O of the pile foundation 1 to be tested. The distances are equal; when four indwelling pipes 2 are set up in the same pile foundation 1 to be tested, as shown in Figures 11 to 13, the four indwelling pipes 2 are symmetrically distributed at 90°, and the four indwelling pipes 2 are respectively arranged in Figure 11 on the line segments OA, OB, OC and OD in , and the distances between the four indwelling pipes 2 and the center point O of the pile foundation 1 to be measured are equal.
进一步的，在所述步骤S2中，施加激励的方式为无偏心竖向激励加载方式，即在所有加速度传感器3上方的桩身中心处施加竖向的测试激励，并由所述的若干加速度传感器3同步采集速度响应时程曲线。Further, in the step S2, the excitation method is a non-eccentric vertical excitation loading method, that is, a vertical test excitation is applied at the center of the pile above all the acceleration sensors 3, and the acceleration sensors are 3. Synchronously collect the speed response time history curve.
优选的，所述加速度传感器3的安装高度低于承台4的下端面。Preferably, the installation height of the acceleration sensor 3 is lower than the lower end surface of the platform 4 .
具体的，在所述步骤S2中，加速度传感器3采集速度响应时程曲线时，对速度响应时程曲线进行预处理的过程包括：对于竖向的测试激励，每个加速度传感器3需采集竖向响应成分，采集的速度信号应进行无量纲化处理，使其无量纲速度位于-1～1之间。Specifically, in step S2, when the acceleration sensor 3 collects the velocity response time history curve, the process of preprocessing the velocity response time history curve includes: for vertical test excitation, each acceleration sensor 3 needs to collect vertical As for the response component, the collected velocity signal should be dimensionally processed so that its dimensionless velocity is between -1 and 1.
更进一步的，在所述步骤S2中，对速度响应时程曲线进行预处理的过程还包括：在振动传感器检测到振动信号后，进行信号放大和滤波，消除信号中的噪声影响，并对信号进行采样、转换和存储。其中，对振动信号进行信号放大和滤波，并对信号进行采样、转换和存储为本领域的常规技术手段，其详细过程，在此不再赘述。Furthermore, in step S2, the process of preprocessing the speed response time history curve also includes: after the vibration sensor detects the vibration signal, signal amplification and filtering are performed to eliminate the noise influence in the signal, and the signal is Sampling, converting and storing. Among them, amplifying and filtering the vibration signal, and sampling, converting and storing the signal are conventional technical means in this field, and the detailed process will not be described again here.
进一步的，在所述步骤S3中，在所述轴向多点行波分解法模型中，进行数据处理与分析的过程包括：Further, in step S3, in the axial multi-point traveling wave decomposition method model, the process of data processing and analysis includes:
S31、确定单位走时Δt为所述加速度传感器3中相邻传感器竖向间距与振动波波速的比值；S31. Determine the unit travel time Δt as the ratio of the vertical distance between adjacent sensors in the acceleration sensor 3 and the vibration wave speed;
S32、将上方传感器和下方传感器所采集的速度响应时程曲线分别前移1个单位走时Δt，即朝时间轴负方向移动1个单位走时Δt，然后针对两条移动后的速度响应时程曲线，分别取时间轴上非负部分的信号数据作为处理后时程曲线，并对末尾进行补零使其与原始速度响应时程曲线的数据长度一致，以便于后续求差；其中，按照上下高度，确定所述的若干加速度传感器3中位于中间高度的中间传感器，并将位于中间传感器上方的传感器记为上方传感器，对应的，并将位于中间传感器下方的传感器记为下方传感器；S32. Move the speed response time history curves collected by the upper sensor and the lower sensor forward by 1 unit of travel time Δt respectively, that is, move 1 unit of travel time Δt in the negative direction of the time axis, and then focus on the two moved speed response time history curves. , respectively take the non-negative part of the signal data on the time axis as the processed time history curve, and pad zeros at the end to make it consistent with the data length of the original speed response time history curve, so as to facilitate subsequent difference calculation; among them, according to the upper and lower height , determine the middle sensor located at the middle height among the several acceleration sensors 3, and record the sensor located above the middle sensor as the upper sensor, and correspondingly, record the sensor located below the middle sensor as the lower sensor;
S33、根据信号的传输规律，将处理后曲线与中间传感器所采集的速度响应时程曲线作差，其结果即等效于通过中间传感器位置的上、下行波分别与其前移2个单位走时曲线作差；因此，将上方传感器的处理后时程曲线与中间传感器所采集的速度响应时程曲线作差，得到第一差值曲线，其等效为中间传感器的上行波的差值曲线；将下方传感器的处理后时程曲线与中间传感器所采集的速度响应时程曲线作差，得到第二差值曲线，其等效为中间传感器的下行波的差值曲线。S33. According to the transmission law of the signal, make a difference between the processed curve and the speed response time history curve collected by the middle sensor. The result is equivalent to the upward and downward traveling waves passing through the position of the middle sensor and their travel time curves moved forward by 2 units respectively. Make a difference; therefore, make a difference between the processed time history curve of the upper sensor and the velocity response time history curve collected by the middle sensor to obtain the first difference curve, which is equivalent to the difference curve of the upgoing wave of the middle sensor; The processed time history curve of the lower sensor is compared with the speed response time history curve collected by the middle sensor to obtain a second difference curve, which is equivalent to the difference curve of the downgoing wave of the middle sensor.
S34、对本发明中激励位于传感器上方的测试条件而言，在前2个单位走时内，下行波应等于中间传感器时程曲线初段，而上行波由于尚未产生应等于零，由此可以对中间传感器上行波和下行波的差值曲线分别进行还原，得到中间传感器完整的上行波曲线和下行波曲线；具体的，在本发明中，可通过数据迭代的方式对上、下行波的差值曲线进行还原；S34. For the test conditions in the present invention where the excitation is located above the sensor, within the first two unit travel times, the downgoing wave should be equal to the initial section of the time history curve of the middle sensor, while the upgoing wave should be equal to zero because it has not yet been generated. Therefore, the upward wave of the middle sensor can be The difference curves of the upgoing and downgoing waves are restored respectively to obtain the complete upgoing wave curve and downgoing wave curve of the intermediate sensor; specifically, in the present invention, the difference curves of the upgoing and downgoing waves can be restored through data iteration. ;
S35，针对中间传感器所在位置，将下行波看作输入，上行波看作输出，通过傅里叶积分变换，在频域内将上行波和下行波的傅里叶变换结果之比作为下方桩身的泛频响函数；对泛频响函数施加虚拟半正弦激励，通过将虚拟半正弦激励与泛频响函数在频域内相乘或在时域内卷积，得到剔除上部结构复杂振动特性的虚拟速度响应曲线；根据该虚拟速度响应曲线确定桩底反射时间区间，以及桩长预测范围；S35, for the position of the middle sensor, the downgoing wave is regarded as the input and the upgoing wave is regarded as the output. Through Fourier integral transformation, the ratio of the Fourier transform results of the upgoing wave and the downgoing wave is used as the ratio of the Fourier transform results of the lower pile body in the frequency domain. Over-frequency response function: apply a virtual half-sine excitation to the over-frequency response function, and multiply the virtual half-sine excitation and the over-frequency response function in the frequency domain or convolve in the time domain to obtain a virtual velocity response that eliminates the complex vibration characteristics of the upper structure Curve; determine the pile bottom reflection time interval and pile length prediction range based on the virtual velocity response curve;
S36，获取基桩振动解析解，并通过在前述桩长预测范围内调整解析解中的桩长，得到不同桩长下的理论解速度响应曲线；针对不同桩长下的理论解速度响应曲线，需要通过拟合的方式来确定最佳的桩长，因此可将前述虚拟速度响应曲线和不同桩长下的理论解速度响应曲线经过小波变换，再对两条小波变换后的响应曲线在桩底反射时间区间内的数据段进行拟合，确定使拟合数据均方根误差最小的解析解桩长，即可将其作为当前待测桩基1的桩长最优估计值，实现对桩身完整性的判断。S36, obtain the analytical solution of foundation pile vibration, and obtain the theoretical solution velocity response curve under different pile lengths by adjusting the pile length in the analytical solution within the aforementioned pile length prediction range; for the theoretical solution velocity response curve under different pile lengths, The optimal pile length needs to be determined by fitting. Therefore, the aforementioned virtual velocity response curve and the theoretical solution velocity response curve under different pile lengths can be subjected to wavelet transformation, and then the two wavelet transformed response curves are calculated at the bottom of the pile. The data segments within the reflection time interval are fitted, and the analytical solution pile length that minimizes the root mean square error of the fitted data is determined, which can be used as the optimal estimate of the pile length of the current pile foundation 1 to be measured, so as to realize the analysis of the pile body. Integrity judgment.
通过S35获得剔除上部结构复杂振动特性的虚拟速度响应曲线，根据传统低应变方法的经验可以大致判断桩长。为了得到更加精确的桩长，一种方法可以使用基桩振动解析解，获取基桩振动解析解，并通过在前述桩长预测范围内调整解析解中的桩长，得到不同桩长下的理论解速度响应曲线；针对不同桩长下的理论解速度响应曲线，需要通过拟合的方式来确定最佳的桩长，将前述虚拟速度响应曲线和每一种桩长下的理论解速度响应曲线经过小波变换，再对两条小波变换后的响应曲线在桩底反射时间区间内的数据段进行拟合，确定使拟合数据均方根误差最小的解析解桩长，并将其作为当前待测桩基的桩长最优估计值，实现对桩身完整性的判断；另一种方法可以使用机器学习，建立各种桩长下的虚拟速度响应曲线的数据库，通过机器学习后进行桩基力学信息的自动化智慧化识别。The virtual velocity response curve that eliminates the complex vibration characteristics of the superstructure is obtained through S35, and the pile length can be roughly determined based on the experience of the traditional low-strain method. In order to obtain a more accurate pile length, one method can be to use the analytical solution of foundation pile vibration to obtain the analytical solution of foundation pile vibration, and by adjusting the pile length in the analytical solution within the aforementioned pile length prediction range, obtain the theoretical results under different pile lengths. Solve the velocity response curve; for the theoretical velocity response curve under different pile lengths, it is necessary to determine the best pile length through fitting. Combine the aforementioned virtual velocity response curve with the theoretical velocity response curve under each pile length. After wavelet transformation, the two wavelet-transformed response curves are then fitted to the data segments within the pile bottom reflection time interval, and the analytical solution pile length that minimizes the root mean square error of the fitted data is determined and used as the current length to be treated. Measure the optimal estimate of the pile length of the pile foundation to judge the integrity of the pile body; another method can use machine learning to establish a database of virtual velocity response curves under various pile lengths, and perform pile foundation analysis after machine learning Automatic and intelligent identification of mechanical information.
本发明中，可根据该虚拟速度响应曲线，由一维杆或梁振动理论确定桩底反射时间区间，并根据该桩底反射时间区间以及振动波速确定预测的桩长范围。In the present invention, the pile bottom reflection time interval can be determined based on the one-dimensional rod or beam vibration theory based on the virtual velocity response curve, and the predicted pile length range can be determined based on the pile bottom reflection time interval and vibration wave speed.
本发明中测得的物理参数主要是桩长和桩身完整性，其中，根据桩底反射点，通过一维杆件振动理论可以计算出埋设在土中的桩长；对于完整桩，所得到的预测长度应与实际长度相同；对于缺陷桩，根据反射区所预测长度是缺陷位置的深度。The physical parameters measured in the present invention are mainly pile length and pile body integrity. According to the reflection point at the bottom of the pile, the length of the pile buried in the soil can be calculated through the one-dimensional rod vibration theory; for a complete pile, the obtained The predicted length should be the same as the actual length; for defective piles, the predicted length based on the reflection zone is the depth of the defect location.
进一步的，在所述步骤S36中，所述基桩振动解析解可为自由桩顶受横向水平激励的桩身解析解。Further, in the step S36, the analytical solution of foundation pile vibration may be the analytical solution of the pile body with the top of the free pile subject to transverse horizontal excitation.
在发明中，通过无偏心竖向激励加载方式、结合行波分解、数据平移处理和构建泛频响函数来消除在低应变检测中上部结构振动带来的复杂影响，同时保存了中间传感器下方桩身全部信息，可有效提高检测的准确度。In the invention, the complex influence of the vibration of the upper structure in low strain detection is eliminated by using a non-eccentric vertical excitation loading method, combined with traveling wave decomposition, data translation processing and the construction of a frequency response function, while preserving the piles under the middle sensor. All the information about the body can be effectively improved the accuracy of detection.
进一步的，在所述步骤S4中，根据轴向多点行波分解法模型输出的数据采取的应对措施包括但不限于缺陷位置修复加固、补桩，以及加强管道的保养和管理等。Further, in step S4, the countermeasures taken based on the data output by the axial multi-point traveling wave decomposition method model include but are not limited to repair and reinforcement of defective locations, patching piles, and strengthening the maintenance and management of pipelines.
进一步的，在所述步骤S4中，随着检测数据的积累，可以建立各种桩长下的虚拟速度响应曲线的数据库，通过机器学习后进行桩基力学信息的自动化智慧化识别，学习后希望达到的效果为：对于一个速度响应曲线，能够判断出桩的类型是完整桩还是缺陷桩。Further, in step S4, with the accumulation of detection data, a database of virtual velocity response curves under various pile lengths can be established, and automatic and intelligent identification of pile foundation mechanical information can be performed through machine learning. After learning, it is hoped that The effect achieved is: for a velocity response curve, it can be judged whether the type of pile is a complete pile or a defective pile.
进一步的，所述桩顶留置管内拾振检测方法，还包括步骤：Further, the method for detecting vibration in the pile top indwelling pipe also includes the steps:
S5，报告输出：根据检测结果生成检测报告，在检测报告中明确桩基的基础信息、检测方法和数据分析结果；影响桩基安全性的异常区域；应采取的措施和建议。S5, report output: generate a test report based on the test results, and clarify the basic information of the pile foundation, test methods and data analysis results in the test report; abnormal areas that affect the safety of the pile foundation; measures and suggestions that should be taken.
作为本申请的一些实施例，所述桩基的基础信息包括但不限于桩长、桩身完整性等。As some embodiments of this application, the basic information of the pile foundation includes but is not limited to pile length, pile body integrity, etc.
综上可知：现有的低应变检测技术是在出露地表的桩身上竖向等间距布置若干个加速度传感器，对于已经建成的建筑，由于桩基都在地下，很难在桩身上布置加速度传感器。而本发明可以通过桩顶留置管2检测深埋固定在地下的钢筋混凝土桩基内的损伤、缺陷等问题，用于解决建筑服役期间对桩基质量的监测问题以及在灾后对建筑桩基损坏程度的评定问题，对于旧房加固、房屋加盖有重要的指导作用。因此，本发明提供的桩顶留置管内拾振检测技术可以有效地解决以上技术问题，提高检测准确性、效率和降低成本，对于确保桩基安全起到积极的促进作用。In summary, it can be seen that the existing low-strain detection technology is to arrange several acceleration sensors at equal intervals vertically on the piles exposed on the surface. For already-built buildings, since the pile foundations are underground, it is difficult to arrange acceleration sensors on the piles. . The present invention can detect damage, defects and other problems in the reinforced concrete pile foundation buried deep underground through the pile top retention pipe 2, and is used to solve the problem of monitoring the quality of the pile foundation during the service of the building and the damage to the building pile foundation after the disaster. The assessment of degree plays an important guiding role in the reinforcement and construction of old houses. Therefore, the vibration pickup detection technology provided by the present invention can effectively solve the above technical problems, improve detection accuracy, efficiency and reduce costs, and play a positive role in ensuring the safety of pile foundations.
上面结合附图对本申请的实施例进行了描述，在不冲突的情况下，本申请中的实施例及实施例中的特征是可以相互组合的，本申请并不局限于上述的具体实施方式，上述的具体实施方式仅仅是示意性的，而不是限制性的，本领域的普通技术人员在本申请的启示下，在不脱离本申请宗旨和权利要求所保护的范围情况下，还可做出很多形式，均属于本申请的保护之内。The embodiments of the present application are described above in conjunction with the accompanying drawings. The embodiments and features in the embodiments can be combined with each other without conflict. The present application is not limited to the above-mentioned specific implementations. The above-mentioned specific embodiments are only illustrative and not restrictive. Under the inspiration of this application, those of ordinary skill in the art can also make other modifications without departing from the purpose of this application and the scope protected by the claims. Many forms fall within the protection of this application.
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| CN202311396106.3ACN117451843A (en) | 2023-10-26 | 2023-10-26 | Pile top indwelling pipe internal vibration pickup detection method |
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| CN202311396106.3ACN117451843A (en) | 2023-10-26 | 2023-10-26 | Pile top indwelling pipe internal vibration pickup detection method |
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| CN202311396106.3APendingCN117451843A (en) | 2023-10-26 | 2023-10-26 | Pile top indwelling pipe internal vibration pickup detection method |
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| CN (1) | CN117451843A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119598153A (en)* | 2024-12-05 | 2025-03-11 | 中交四航工程研究院有限公司 | Pile foundation damage identification method, device, equipment and storage medium |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119598153A (en)* | 2024-12-05 | 2025-03-11 | 中交四航工程研究院有限公司 | Pile foundation damage identification method, device, equipment and storage medium |
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