CN108169002A - A kind of reduced scale test model and method for testing steel-concrete composite beam Creep Characteristics - Google Patents

Abstract

The invention discloses a kind of structure testing methods of field of civil engineering.For steel-concrete combination beam full size long duration load test operation difficult problem, a kind of scaled model is invented, the model component is simple, small, the small spatial position such as can be placed under desk；Instrument is using vibrating string extensometer and thousand points of meters with position contrast test, it is ensured that the accuracy of result；Data collection uses Portable data acquisition instrument, can carry out energization acquisition for a long time, also can manually acquire；Result of the test can be compared with written calculation result.The data that experiment is collected can accurately describe mechanical characteristic of the steel-concrete structure under action of long-term load, disclose the long-term Laws of Mechanics of combination beam.

Description

Translated fromChinese

一种测试钢-混凝土组合梁徐变特性的缩尺试验模型及方法A scaled-scale test model and method for testing the creep characteristics of steel-concrete composite beams

技术领域technical field

本发明专利属于土木工程结构试验技术领域，涉及一种测试钢-混凝土组合梁徐变特性的缩尺试验模型及方法。The patent of the invention belongs to the technical field of civil engineering structure test, and relates to a scale test model and method for testing the creep characteristics of steel-concrete composite beams.

背景技术Background technique

钢-混凝土组合梁具有显著的技术经济效益和广泛的应用前景。该结构在使用期间，组合梁中的混凝土会产生徐变，钢梁对该变形的约束将导致静定组合梁内部发生截面应力重分布，对于超静定组合梁还会引起随时间变化的徐变(收缩)次内力，从而导致组合梁截面最终应力状态的改变，其值可达弹性变形的数倍之多，这对挠度要求严格的结构非常不利。Steel-concrete composite beams have significant technical and economic benefits and broad application prospects. During the use of the structure, the concrete in the composite beam will produce creep, and the restraint of this deformation by the steel beam will lead to the redistribution of cross-sectional stress inside the statically indeterminate composite beam, and for the statically indeterminate composite beam, it will also cause creep that changes with time. Change (shrink) the internal force, resulting in a change in the final stress state of the composite beam section, which can be several times the elastic deformation, which is very unfavorable for structures with strict deflection requirements.

然而徐变对钢-混凝土组合梁性能的影响十分复杂，包含了相当数量的不定因素，几乎所有影响徐变的因素连同它们产生的结果本身就是随机变量，为了获取这些参数，通常需要进行足尺试验。由于徐变属于长期力学性能，费时很长，一般要持续1年以上，受环境扰动和实验室空间影响较大，同时该试验需要长期测数据，而传统应变片读数需要通交流电，且观测的是短期的数据，达不到稳定、长期、准确获取试件有效数据的目的，因此组合梁的足尺长期荷载试验实现起来是很困难的。However, the effect of creep on the performance of steel-concrete composite beams is very complex, including a considerable number of uncertain factors. Almost all factors affecting creep and their results are random variables. In order to obtain these parameters, it is usually necessary to conduct a full-scale test. Since creep is a long-term mechanical property, it takes a long time, usually lasts for more than one year, and is greatly affected by environmental disturbance and laboratory space. At the same time, the test requires long-term measurement data, while the traditional strain gauge reading requires alternating current, and the observed It is short-term data, which cannot achieve the purpose of obtaining stable, long-term and accurate effective data of specimens. Therefore, it is very difficult to realize the full-scale long-term load test of composite beams.

发明内容Contents of the invention

针对钢-混凝土组合梁足尺长期荷载试验操作困难问题，发明一种缩尺模型，该模型构件简单，体积小，可放在办公桌底下等小空间位置；仪器采用振弦式应变计与千分计同位对比测试，确保结果的准确性；数据收集采用便携式数据采集仪，可长期进行通电采集，也可人工采集；试验结果可以和笔算结果进行对比。Aiming at the difficulty in operating the full-scale long-term load test of steel-concrete composite beams, a scaled-down model is invented. The comparison test of the sub-meter and the same position ensures the accuracy of the results; the data collection adopts a portable data acquisition instrument, which can be collected by power-on for a long time, and can also be collected manually; the test results can be compared with the results of written calculations.

附图说明Description of drawings

图1是缩尺模型纵轴方向示意图；Fig. 1 is a schematic diagram of the longitudinal axis direction of the scale model;

图2是缩尺模型横向截面尺寸示意图；Fig. 2 is a schematic diagram of the transverse section size of the scale model;

图3是缩尺模型透视图。Fig. 3 is a perspective view of a scale model.

图中各标号为：1是钢-混凝土组合梁；2是标准钢加载块；3是标准钢垫块；4是百分表；5是振弦式应变计；6是带标距千分表；7是便携式数据采集仪；8三角支座；9半弧形支座；10带肋钢筋；11钢板。The labels in the figure are: 1 is steel-concrete composite beam; 2 is standard steel loading block; 3 is standard steel pad; 4 is dial gauge; 5 is vibrating wire strain gauge; 6 is dial gauge with gauge ; 7 is a portable data acquisition instrument; 8 triangular support; 9 semi-arc support; 10 ribbed steel bar; 11 steel plate.

具体实施方式Detailed ways

本发明专利的内容是通过下面的技术方案实现的。The content of the patent of the present invention is realized through the following technical solutions.

1）在人为扰动相对较小的室内场所，操作空间占地面积约4平方米处架设支座8和支座9，制作钢-混凝土构件1，构件1的尺寸可以按实际尺寸等比例缩小，钢板-钢筋模式是便于把手算结果和试验结果对比分析；支座8和9上各放一块垫块3；构件1养护7天放置到加垫块3的支座上。1) In indoor places where human disturbance is relatively small, the operating space covers an area of about 4 square meters to erect support 8 and support 9, and make steel-concrete member 1. The size of member 1 can be reduced in proportion to the actual size, The steel plate-reinforcing bar model is convenient for comparison and analysis of calculation results and test results; a spacer 3 is placed on each support 8 and 9; component 1 is placed on the support with spacer 3 after 7 days of maintenance.

2）于构件放置到支座的当天（即构件养护的第7天），将一个振弦式应变计5和一个带标距千分表6分别安装在构件上边缘、下边缘钢板11和混凝土上下边缘；5和6安装在同一位置，进行数据对比。在构件跨中和支座8、9处分别安装一个百分表。2) On the day when the component is placed on the support (that is, the seventh day of component maintenance), install a vibrating wire strain gauge 5 and a gauge gauge 6 on the upper edge of the component, the lower edge steel plate 11 and the concrete The upper and lower edges; 5 and 6 are installed at the same position for data comparison. Install a dial indicator at the mid-span of the component and at the supports 8 and 9 respectively.

3）于仪器安装的当天（即构件养护的第7天），将标准钢加载块2放在构件的三等分点处，同时用便携式数据采集仪7接通正弦式应变计5进行第一天测量，后续测量的时间点为：第1个月每天测量一次，第2、第3个月每3天测量一次，第4至第12个月每7天测量一次，时间跨度为一年。一年以后可以每隔10天测量一次。3) On the day of instrument installation (that is, the 7th day of component maintenance), place the standard steel loading block 2 at the third point of the component, and connect the sinusoidal strain gauge 5 with the portable data acquisition instrument 7 for the first The time points for follow-up measurements are: once a day in the first month, every 3 days in the second and third months, and every 7 days in the 4th to 12th months, with a time span of one year. After one year, it can be measured every 10 days.

4) 每一个测点处的数据可用振弦式应变计5的结果与带标距千分表测量的结果进行对比；同时试验结果可与手算的结果进行对比。4) The data at each measuring point can be compared with the results of the vibrating wire strain gauge 5 and the measurement results of the dial gauge with gauge; at the same time, the test results can be compared with the results of the hand calculation.

Claims (2)

1. a kind of experimental rig and test method for measuring composite structure Creep Characteristics, it is characterised in that：Component is simple, volumeIt is small, it the small spatial position such as can be placed under desk；Instrument is using vibrating string extensometer and thousand points of meters with position contrast test, it is ensured thatAs a result accuracy；Data collection uses Portable data acquisition instrument, can carry out energization acquisition for a long time, also can manually acquire；ExaminationTesting result can be compared with written calculation result；The data that experiment is collected can accurately describe steel-concrete structure long-termMechanical characteristic under load action discloses the long-term Laws of Mechanics of combination beam.

2. experimental rig as described in claim 1 and test method include component making, instrument Installation And Test scheme, specificallyStep includes：

1）Bearing 8 and bearing are set up at the relatively small indoor spaces of artificial disturbance, about 4 square metres of operating space floor space9, steel-concrete component 1 is made, the size of component 1 can be easy for by actual size scaled down, steel plate-reinforcing bar patternManual calculation result and comparison of test results are analyzed；One piece of cushion block 3 is respectively put on bearing 8 and 9；Component 1 conserves 7 days and is placed into cushioning blockOn 3 bearing；

2）The same day of bearing is placed into component（That is the 7th day of component conservation）, by a vibrating string extensometer 5 and a band markComponent top edge, lower edge steel plate 11 and concrete lower edges are separately mounted to away from amesdial 6；5 and 6 are mounted on same positionIt puts, carries out data comparison.A dial gauge is installed respectively at component span centre and bearing 8,9；

3）In the same day of instrument installation（That is the 7th day of component conservation）, standard steel loading blocks 2 are placed on to the trisection point of componentPlace, while connect sinusoid strain gauge 5 with Portable data acquisition instrument 7 and carry out measurement in first day, the time point subsequently measured be：It measures once within 1st month, is measured within every 3 days the 2nd, the 3rd month once daily, measure within every 7 days the 4th to 12nd month primary, the timeSpan is 1 year.It can be measured after 1 year every 10 days primary；

4) data at each measuring point can be carried out with the result of vibrating string extensometer 5 with the result measured with gauge length amesdialComparison；Result of the test can be compared with the result of hand computation simultaneously.