CN109797786A - Excavation of foundation pit model test apparatus and application method based on earth's surface water penetration - Google Patents

Abstract

Translated fromChinese

基于地表水渗透的基坑开挖模型试验装置及使用方法；包括模型箱、人工湖设计水槽、基坑支护结构、角钢架和量测系统；模型箱为透明的正方形箱体，方便观测试验中地表水对基坑围护壁的渗透情况以及基坑支护结构的位移和土体的变形；人工湖设计水槽用于模拟人工湖的渗透；基坑支护结构通过角钢架与模型箱连接固定，其上布置监测仪器连接量测系统；模拟受地表水渗透作用下基坑开挖变形的响应情况，观察和研究地表水对基坑围护壁的渗水影响范围及对支护结构开挖变形的影响。本发明结构合理，操作简便，可用于模拟地表水渗透作用下最危险开挖工况下的基坑受力和变形的影响，为相关基坑开挖模型试验和研究提供了一种有效方案。

Model test device for foundation pit excavation based on surface water infiltration and its use method; including model box, artificial lake design water tank, foundation pit support structure, angle steel frame and measurement system; the model box is a transparent square box, which is convenient for observation In the test, the infiltration of surface water to the surrounding walls of the foundation pit, the displacement of the foundation pit supporting structure and the deformation of the soil body; the artificial lake design water tank is used to simulate the infiltration of the artificial lake; the foundation pit supporting structure is connected by the angle steel frame and the model The box is connected and fixed, and the monitoring instrument is arranged on it to connect the measurement system; simulate the response of the excavation deformation of the foundation pit under the infiltration of surface water, observe and study the influence range of the surface water on the surrounding walls of the foundation pit and the impact on the supporting structure The effect of excavation deformation. The invention has reasonable structure and simple operation, can be used for simulating the influence of foundation pit force and deformation under the most dangerous excavation working condition under the action of surface water infiltration, and provides an effective solution for relevant foundation pit excavation model test and research.

Description

Excavation of foundation pit model test apparatus and application method based on earth's surface water penetration

Technical field

The invention belongs to foundation pit experimental technique field, in particular to a kind of excavation of foundation pit model examination based on earth's surface water penetrationExperiment device and application method.

Background technique

In recent years, urban construction is fast-developing, and deep-foundation pit engineering increases increasingly, base pit engineering faces deep depth, surface ga(u)geThe new trend that mould is big, ambient enviroment is complicated.It is even more especially that face underground water rich in the deep-foundation pit engineering of strand, riparian areaRichness, the challenges such as construction environment is complicated and difficulty of construction is big.In order to solve influence of the underground water to excavation of foundation pit, in foundation pit constructionPrecipitation is carried out to guarantee that foundation pit carries out construction and excavation under anhydrous conditions to foundation pit underground water frequently with various precipitation facilities, andWhen infiltration feeds surface water under heavy rainfall, man-made lake, surface water can have the effect of lateral runoff in soil layer, at this timeWhen surface water is closer apart from foundation pit supporting construction, the osmosis of surface water can generate certain influence to foundation pit enclosure wall.GroundFoundation pit deformation caused by table water runoff osmosis and destabilization problems are constantly paid high attention in design of deep foundation pit and constructionAnd attention.Using the method simulating excavation of indoor geotechnical model test, it is widely used in geotechnical engineering field,But with regard to how by excavation models to test objective and accurate simulation surface water runoff osmosis to supporting in Excavation ProcessThe deformation of structure influences and the coverage of earth's surface water penetration is still problem in the urgent need to address.

Excavation models test at present considers groundwater effect to the soil pressure of the excavation of foundation pit soil body and the shadow of foundation pit deformationIt rings.The excavation models test for considering constant phreatic table effect has research (the macro thin sight research of Peng Shuquan sand barricade failure mechanism[D] Tongji University, 2007.) use film to connect retaining wall and model casing by the method for smearing epoxy resin after corona, it shouldMethod can obtain excess pore water pressure, soil pressure and foundation pit deformation data in the test soil body, but film corona technique is more multipleMiscellaneous, tearing may occur in moving process for film or since soil particle friction leads to breakage, Wu Fashun when lateral diaphragm wall displacement is largerBenefit completes test or carries out repeating test.Consider the excavation models test that WATER LEVEL CHANGES influences, there is the research (strand Sun WeiThe test of regional deep basal pit character and theoretical research [D] Zhejiang University, 2015.) using the method for fixed retaining wall, this methodThe situation of change of excess pore water pressure in the soil body can only be obtained, accurate soil pressure variation and foundation pit deformation number can not be obtainedAccording to there are still larger differences with response condition of the practical base pit engineering under the effect of dynamic level of ground water.But such research is uncomfortableFor the chemosmotic excavation of foundation pit situation of surface water runoff.Therefore, more easy, accurate simulation surface water runoff infiltration is madeIt is to need to solve in excavation of foundation pit model test when seeping to feed surface water under heavy rainfall, man-made lake with lower excavation of foundation pit situationMain problem certainly.

A large number of experiments is research shows that excavation of foundation pit completes the most danger that operating condition is usually excavation of foundation pit to hole bottom, that is, excavation of foundation pitDangerous section's condition.In practical projects, it is complete that the case where numerous foundation pit deformations is excessive or unstable failure also occurs often in excavation of foundation pitAt operating condition.Therefore excavation of foundation pit completes the surface water under operating condition to the infiltration coverage of foundation pit enclosure wall and to supporting constructionThe influence of excavation deformation will become the most important thing in model investigation.

Summary of the invention

In order to overcome the above the deficiencies in the prior art, the present invention provides the excavation of foundation pit model examinations based on earth's surface water penetrationExperiment device and application method are solved and are seeped when feeding to surface water under man-made lake, the problem of modelling of surface water runoff infiltration,And determine earth's surface water penetration coverage and to excavation of foundation pit deformation influence the problems such as.

The technical scheme adopted by the invention is that: based on the excavation of foundation pit model test apparatus of earth's surface water penetration and userMethod, including model casing, foundation pit supporting construction, slotted-angle shelving, man-made lake design sink and measurement system；Test soil is equipped in model casingBody, foundation pit supporting construction, slotted-angle shelving, man-made lake design sink；

The model casing is square box；Facilitate the displacement of observation foundation pit supporting construction and the deformation and examination of soil mass of foundation pitMiddle surface water is tested to the infiltration situation of foundation pit enclosure wall；

The foundation pit supporting construction is connected and fixed by slotted-angle shelving and model casing；The foundation pit supporting construction includes supportingStake, crown beam, waist rail, anchor cable, anchor head, anchoring body and spray armour layer；Between more vertical support piles and more horizontal waist rails etc.It is fixed away from gluing, the top of more support piles and root cap beam casting are fixed；On waist rail between per adjacent two support pilesIt is equipped with through-hole；The anchor head is made of screw bolt and nut, solid with nut after every bolt to be passed through to each through-hole on waist railIt is fixed；All shanks of bolt stretch out nut portion and connect with anchor cable, form the connection of anchor cable and anchor head, are wrapped with anchoring bodyWrap up in the tail end of anchor cable；The spray armour layer includes thin wire gauze and concrete mortar, in support pile, crown beam, waist rail, anchor cable, anchorThe body structure surface of head composition covers thin wire gauze and fixation, concrete mortar plastering is reused, for simulating the spray mask of foundation pitLayer；The spray armour layer and anchor cable be not in the same side；

The slotted-angle shelving is door type part made of fixing, and the influence for reduction boundary to experimental result prevents foundation pit branchThere is torsional deflection in protection structure, arranges that monitoring instrument connects measurement system thereon；

Described man-made lake design sink is by production mold and casting concrete mortar is made, then is embedded in anchor in model casingThe side of rope, is placed in parallel with foundation pit supporting construction and keeps certain distance；For simulating the infiltration of man-made lake；

The measurement system includes foil gauge, displacement meter, data collecting instrument, computer and camera；Foil gauge passes through transmissionLine connects data collecting instrument；Displacement meter, data collecting instrument connect computer by transmission line；Launch computer corresponding data acquisition softwareRead displacement meter, the data information that data collecting instrument transmission comes；Camera is placed in outside model casing, and one in face of spraying armour layerSide.

The square uncovered box that the model casing is composed of transparent plexiglass plate.

The die size and embedding position dimension of the man-made lake design sink carry out similar Design by full-scale engineeringDiminution ratio obtains.

Support pile, crown beam, waist rail, anchor cable, anchor head, anchoring body and the spray armour layer that the foundation pit supporting construction includesDimensional parameters, location parameter and number parameter are to carry out similar Design diminution ratio by full-scale engineering to obtain.

The slotted-angle shelving is welded by 2 root long angle steel and 1 angle clip, is welded between the head end of 2 root long angle steel shortAngle steel, the angle steel are stainless steel right angle angle steel.

The vertical displacement of the supporting stake top is monitored with stay-supported type displacement sensor, and support pile Horizontal Displacement is adoptedIt is monitored with laser displacement sensor.

The foil gauge is transferred to the signal of data collecting instrument by signal transmssion line, the signal of displacement meter finally transmitsOnto the corresponding data acquisition software of computer, guarantee the synchronous acquisition of all signals during the test.

The data collecting instrument, computer answer exclusive PCR during the test, and position can not move, with guarantee testThe accuracy of data acquisition in the process.

The camera answers exclusive PCR during the test, and position can not move；It can need to add according to shootingLight source.

The man-made lake design sink must be filled the water into sink always during the test keeps full water state, to guaranteeThe base pit engineering environment persistently permeated.

The test soil body filled in the model casing using dry ground as aggregate, bulk density material, internal friction angle sensitive material,Cohesion sensitive material chooses different fillers respectively, by determining model with the horizontal orthogonal experiment design method of four factor fourTest soil layer is configured to obtain with the most similar proportion of original state soil layer.

Compared with prior art, the beneficial effects of the present invention are:

1, the present invention can be simulated and be seeped when feeding to surface water under man-made lake, the base under surface water runoff osmosisEngineering-environment is cheated, keeps full water by designing water filling in sink to the man-made lake being embedded in model casing always during the testState, to guarantee the base pit engineering environment persistently permeated, working principle is simple, and device is simple, installs easy to operate.

2, foundation pit supporting construction is connected and fixed by simple slotted-angle shelving and model casing in the present invention, reduces boundary to testAs a result influence, and support pile is prevented torsional deflection occur；The raw material acquisition that foundation pit supporting construction uses is convenient, at low costIt is honest and clean, it processes easy to assembly；Its relevant dimensional parameters, location parameter and number parameter can carry out similar Design by full-scale engineeringDiminution ratio obtains.

3, the anchor cable in the present invention is mounted on waist rail by anchor head, can need to adjust anchor cable according to model testRoad number and the number of elements of per pass anchor cable etc..

4, the same set of experimental rig in the present invention can carry out the excavation of foundation pit test of multiple groups different soil, reduce to examinationExperimentation cost and modelling time have been saved in the repacking of experiment device, and working principle is simple, easy to operate, have very big realityThe property used.

Detailed description of the invention

Fig. 1 is the front view of model test apparatus；

Fig. 2 is the side view of model test apparatus；

Fig. 3 is the top view of model test apparatus；

Fig. 4 is the sectional view of model test apparatus；

Fig. 5 designs sink three-view diagram for man-made lake；

Fig. 6 is the front view of foundation pit supporting construction；

Fig. 7 is the side view of foundation pit supporting construction；

Fig. 8 is slotted-angle shelving and foundation pit supporting construction connection schematic diagram；

Fig. 9 is anchor head (bolt and nut) and waist rail connection schematic diagram；

Figure 10 is monitoring site arrangement schematic diagram；

Figure 11 is workbench and digital position of camera schematic diagram.

Wherein: 1. model casings；2. man-made lake designs sink；3. foundation pit supporting construction；4. slotted-angle shelving；5. support pile；6. hatBeam；7. waist rail；8. anchor cable；9. anchor head；10. spraying armour layer；11. anchoring body；12. testing the soil body；13. no-welding foil gauge；14.Laser displacement gauge；15. bracing wire displacement meter；16. multi-Channels Data Acquisition；17. laptop；18. digital camera；19.Workbench；20. bolt；21. nut.

Specific embodiment

With reference to the accompanying drawings and examples to the detailed description of the invention.

Embodiment

As shown in Fig. 1~11, the present invention is based on the excavation of foundation pit model test apparatus and application method of earth's surface water penetration, packetsInclude model casing 1, man-made lake design sink 2, foundation pit supporting construction 3, slotted-angle shelving 4 and measurement system；Test soil is equipped in model casing 1Body 12, foundation pit supporting construction 3, slotted-angle shelving 4, man-made lake design sink 2；

The model casing 1 is side length 0.9m, the square uncovered box that the transparent plexiglass plate of δ 10 is composed；Facilitate surface water in observation experiment to the infiltration situation of foundation pit enclosure wall and the displacement of foundation pit supporting construction 3 and soil mass of foundation pitInfiltration situation of the surface water to foundation pit enclosure wall in deformation and test；

The foundation pit supporting construction 3 is connected and fixed by slotted-angle shelving 4 with model casing 1；The foundation pit supporting construction 3 includesSupport pile 5, crown beam 6, waist rail 7, anchor cable 8, anchor head 9, spray armour layer 10 and anchoring body 11；More vertical support piles 5 with moreHorizontal waist rail 7 is equidistantly fixed using strength nail-free glue gluing, and the top of more support piles 5 and a root cap beam 6 use rapid-curing cutbackGypsum pouring molding in mold；5 geometric dimension of support pile: 3.2cm × 3.2cm × 74cm, between support pile 5 and support pile 5Spacing be 4.8cm；7 geometric dimension of waist rail: 2cm × 2cm × 90cm, spacing between waist rail 7 and waist rail 7 are 12cm, firstThe spacing of road waist rail 7 and crown beam 6 is 10cm；It is equidistantly equipped with through-hole on waist rail 7 between per adjacent two support piles 5, is used forFixed anchor head 9；The anchor head 9 uses specification for the bolt 20 of M3x30 and nut 21, and every bolt 20 is passed through on waist rail 7After each through-hole, is fixed with nut 21 and constitute anchor head 9；All 20 bars of bolt stretch out 21 part of nut and anchor cable 8 are used to connectGet up, form the connection of anchor cable 8 and anchor head 9, is the tail end for wrapping up anchor cable 8 using concrete mortar with anchoring body 11；It is describedAnchor cable 8 is the steel strand wires of diameter 3mm；The spray armour layer 10 includes thin wire gauze and concrete mortar, in support pile 5, crown beam6, the body structure surface that waist rail 7, anchor cable 8, anchor head 9 form covers thin wire gauze and fixation, reuses concrete mortar plastering, is used forSimulate the spray armour layer 10 of foundation pit；

The slotted-angle shelving 4 is door type part made of welding, by welding 1 0.9m's between the head end of 2 1.04m angle steelAngle steel, the angle steel are stainless steel right angle angle steel, to reduce influence of the boundary to experimental result, prevent foundation pit supporting construction 3There is torsional deflection, arranges that monitoring instrument connects measurement system thereon；

Described man-made lake design sink 2 is by production mold and casting concrete mortar is made, then is embedded in model casingThe side of anchor cable, is placed in parallel with foundation pit supporting construction and keeps certain distance；For simulating the infiltration of man-made lake；It is described artificialThe die size and embedding position dimension of lake design sink 2 carry out similar Design diminution ratio by full-scale engineering and obtain.It is describedMan-made lake designs sink 2 must fill the water holding full water state into sink always during the test, to guarantee the base persistently permeatedCheat engineering-environment.

The measurement system includes that no-welding foil gauge 13, laser displacement gauge 14, bracing wire displacement meter 15, multi-channel data are adoptedCollect instrument 16, laptop 17, digital camera 18 and workbench 19；Multi-channel data is arranged on the workbench 19 to adoptCollect instrument 16 and laptop 17, the no-welding foil gauge 13 passes through signal transmssion line connecting multi-channel data collecting instrument 16；The laser displacement gauge 14, bracing wire displacement meter 15, multi-Channels Data Acquisition 16 connect laptop by signal transmssion line17；The laptop 17 starts the acquisition of corresponding data acquisition software and passes through laser displacement gauge 14, bracing wire displacement meter 15, multi-passThe data information that track data Acquisition Instrument 16 transmits guarantees the synchronous acquisition of all signals during the test；The multi-passTrack data Acquisition Instrument 16, laptop 17 answer exclusive PCR during the test, and position can not move, to guarantee to tryThe accuracy that data acquire during testing；The digital camera 18 is placed in outside model casing 1, the side in face of spraying armour layer,It can be needed to add light source according to shooting；The digital camera 18 answers exclusive PCR during the test, and position can not occurIt moves.No-welding foil gauge 13 uses HY120-20AA, and laser displacement gauge 14 uses Britain very still ZLDS102, bracing wire displacement meter15 test 5G202 using East China, and multi-Channels Data Acquisition 16 builds nation observing and controlling ZL-12000P using ZBM.

According to geometric similarity ratio, former base cheats cutting depth 14.5m, model excavation of foundation pit depth 58cm；Former 5 build-in of support pileSoil depth 4m, 5 build-in soil depth 16cm of model support pile；Original place matter soil layer number is numerous, according to the similar principle that is harmonious to originalSoil layer is simplified and does likelihood ratio processing；Simplify soil layer after similar processing and be divided into 5 layers: 1. miscellaneous fill, thickness 0.12m；2. powderMatter clay, thickness 0.20m；3. silty clay, thickness 0.26m；4. silty clay, thickness 0.22m；5. coarse sand, thickness 0.10m.

This model test chooses Fuxin locality dry ground as aggregate, bulk density material selection blanc fixe, and internal friction angle is quickFeel material selection bentonite, cohesion sensitive material chooses grey calcium.It is true with the horizontal orthogonal experiment design method of four factor fourDetermine model test soil layer and the most similar proportion of original-pack soil layer, by soil layer 3. for, first by 10 groups of direct shear tests it is preliminaryIt determines when blanc fixe is aggregate dry ground content 35%, water content 25%, grey calcium content is aggregate 20% and bentonite is boneWhen expecting 40%, c, φ value of the 3. number soil layer made are closer to original state soil layer.Situation is matched based on this, soil layer is carried out justExperimental design is handed over, is analyzed to obtain the soil layer proportion closer to original place layer according to comparison of test results, carries out allocation models soil.OtherSoil layer is matched according to the above method.

The course of work of the invention includes the following steps:

Support pile 5, crown beam 6, waist rail 7, anchor cable 8, anchor head 9, the spray processing of armour layer 10 are assembled into pattern foundation pit supporting structure by step 1.Structure 3；No-welding foil gauge 13 is pasted in the rational position of the support pile 5 of foundation pit supporting construction 3；

Assembled foundation pit supporting construction 3 is connected and fixed by slotted-angle shelving 4 with model casing 1 by step 2., reduces boundary pairThe influence of experimental result prevents foundation pit supporting construction 3 from rotational deformation occur；

Step 3. is layered the filling test soil body 12 into model casing 1 and tamps, whenever filling to the corresponding height of each road anchor cable 8When adjust the anchor cable 8 i.e. position of steel strand wires and with concrete mortar serve as anchoring body 11 wrap up anchor cable 8 tail portion, then proceed toIt loads each layer test soil body 12 and tamps；

When step 4. soil body 12 to be tested will fill completion, man-made lake design sink 2 is embedded in anchor cable in model casing 1Side, be placed in parallel with foundation pit supporting construction and keep certain distance；Continue the landfill test soil body 12 and man-made lake designs water2 surface of slot maintains an equal level；Banketing after completing, water filling keeps full water state into man-made lake design sink 2；

Step 5. sets up 2 laser displacement gauge 14 and 2 bracing wire displacement meters 15 on model casing 1 and slotted-angle shelving 4 respectively, pointNot Jian Ce foundation pit supporting construction 3 Horizontal Displacement and stake top vertical displacement；Then no-welding foil gauge 13 is passed through into signalTransmission line is connected with 1 multi-Channels Data Acquisition 16；Again by laser displacement gauge 14, bracing wire displacement meter 15, multichannel numberIt is connected on laptop 17 according to Acquisition Instrument 16 by signal transmssion line, starts corresponding data acquisition software and carries out debugging workMake；1 digital camera 18 is placed in outside model casing 1, the side (cannot move during the test) in face of spraying armour layer,Camera parameter is adjusted, the automatic shooting time of setting digital camera 18 is interval 20s；It, can be in number if laboratory insufficient lightLed light source is added in 18 two sides of code camera；No-welding foil gauge under original state is tested using 17 acquisition and recording of laptop13, the reading of laser displacement gauge 14, bracing wire displacement meter 15 shoots the test soil under test original state using digital camera 1812 photo of body；

Step 6. carries out foundation pit divided working status excavation in the side that camera faces, and in entire soil mass of foundation pit digging processMeasurement system normal operation is kept, corresponding datagraphic information is recorded, until excavation of foundation pit is completed.

This model test monitoring content mainly has support pile 5 to push up horizontal displacement, support pile 5 pushes up soil after vertical displacement and stakeBody sedimentation.Support pile 5 from left to right number be 1.-Stay-supported displacement sensing is used in the vertical displacement of number stake, 5 stake top of support pileDevice monitoring, 5 Horizontal Displacement of support pile are monitored using laser displacement sensor, and monitoring point is arranged at the 1/2 of supporting constructionWith 1/4 at i.e. 10. number stake andIn number stake, 15 foil gauges are posted on model support pile 5, respectively 5., 10. andIt is pasted in number stake5, the foil gauge of stickup needs to do insulation processing, and sensitivity coefficient is 2.0 ± 1%, 2 laser displacement gauge 14 and 2 bracing wire positionsMove meter 15 be separately positioned on 10. number stake andOn the model casing 1 in 6 front of crown beam (in face of spray armour layer side) of number stake and angleThe vertical stays position of steelframe 4；Monitoring point arrangement is as shown in Figure 10 on support pile 5.Test operation platform and digital camera 18Position it is as shown in figure 11.

During the test of entire excavation of foundation pit, full water state is kept by designing water filling in sink 2 to man-made lake always,Guarantee the base pit engineering environment persistently permeated, passes through no-welding foil gauge during the record test of 17 continuous acquisition of laptop13, the reading of laser displacement gauge 14, bracing wire displacement meter 15 shoots earth's surface during entirely testing by triggering digital camera 18The photo that water deforms the permeation effects range of foundation pit walls, the excavation deformation of supporting construction and the test soil body 12.

By no-welding foil gauge 13, laser displacement gauge 14, the bracing wire displacement meter of analyzing 17 acquisition and recording of laptop15 readings obtain the affecting laws that surface water osmosis deforms excavation of foundation pit in the entire digging process of foundation pit；It is logicalCross and image analysis carried out to photo captured by digital camera 18, obtain surface water to the permeation effects range of foundation pit walls, fromAnd learn surface water osmosis to the affecting laws of excavation of foundation pit.

Model test interpretation of result:

1) model test phenomenon analysis:

The lower milliosmolarity of man-made lake is related with regional soil mass property, and range is seeped under different soil properties and is different from, this model testPurpose by carrying out simulation laboratory test to effective penetration range of support pile 5 to different soil property underground water, summarize the engineeringReach the penetration range after stablizing under geological conditions under different soil properties, finally by the similar soil layer of former construction geology condition configuration intoExperimental study of the row surface water to the effective penetration range of branch retaining wall, construction simulation scene.

Model test is divided into four groups, and the purpose of first three groups test is that three kinds of soil properties being related to supporting construction carry out ground respectivelyThe effective penetration range test of table water, with the likelihood ratio and soil layer preparation method make 1., 2., 3. number soil layer, tried respectivelyIt tests.The soil layer of last battery of tests is filled according to original state soil layer, and is monitored to the displacement of support pile 5 and internal force.Test processMiddle holding man-made lake model water is constant and observing time is constant.

Since soil layer is there are anisotropy, permeation pathway of the water in the soil body and soil body nature, porosity and infiltrationProperty it is related, it is desirable to determine that accurately permeation pathway is more difficult, therefore can only determine a rough model to effective permeable faceIt encloses.Man-made lake water penetration is to permeate simultaneously to horizontal direction and vertical direction, this model test mainly considers that surface water is seepingAngle, that is, effective penetration range during thoroughly between horizontal and vertical infiltration.Now only to the 4th group of original state soil layer experimental phenomena intoRow be described in detail: by the soil layer in model casing 1 by same court soil layer be laid with, at the same time under the conditions of, observation 5 table of support pileSituation is permeated in face.When banket layering after, since each soil layer soil mass property and parameter are different, surface water is seeped from a kind of soil layerIt can change therewith to its permeation effects range after another soil layer thoroughly.In terms of test result, model support pile 5 occurs for the first timeAt away from 6 top surface 212mm of crown beam, permeable face length reaches 277mm in steady seepage face.It will affect the conversion of the range likelihood ratio, quiteIt is pushed up at 5.30m~6.93m in permeable areas away from support pile 5, i.e. between first of waist rail 7 and third road waist rail 7, construction siteThe steady seepage face of support pile 5 appears in the place of 5.0m or so for the first time, and there are one with on-site actual situations for model test resultDetermine deviation, but result is closer to, therefore this test model has some reference value.Supplementary explanation: first group of miscellaneous fill examinationIt tests group model support pile 5 and occurs steady seepage face for the first time at away from 6 top surface 192mm of crown beam, permeable face length reaches 232mm.TheThere is steady seepage face at away from 6 top surface 171mm of crown beam for the first time in the silty clay test group model support pile 5 of two groups of second layers,Permeable face length reaches 204mm.There is steady seepage face for the first time in the silty clay test group model support pile 5 of third group third layerAt away from 6 top surface 136mm of crown beam, permeable face length reaches 174mm.Global analysis is in terms of test result, and earth's surface water penetration is in originalThe diffusion angle of soil layer is smaller than the diffusion angle in miscellaneous fill, but bigger than the diffusion angle in silty clay.

2) 3 deformation result of foundation pit supporting construction is analyzed:

From obtained monitoring data it is found that with cutting depth and digging time increase, the vertical position of 5 stake top of support pileShifting is gradually increased.Maximum deformation quantity is the support pile 5 at middle part, and the deflection of maximum value 23.7mm, edge support pile 5 are maximumFor 16.5mm；The vertical displacement of 5 stake top middle section of support pile is greater than the vertical displacement of two sides known to analysis.

As foundation pit constantly excavates, the horizontal displacement of 5 stake top of support pile constantly increases.The support pile 5 at intermediate position is horizontalDisplacement maximum value reaches 19.7mm, and the maximum horizontal displacement of two sides support pile 5 reaches 15.2mm.5 stake top of support pile known to analysisThe horizontal displacement of middle section is greater than the horizontal displacement of two sides.

The resistance-strain sheet data being arranged on support pile 5 is analyzed it can be concluded that support pile 5 is produced in deformation processRaw moment of flexure, and converse according to the likelihood ratio theory moment of flexure of prototype support pile 5.As excavation of foundation pit depth increases, support pile 5Moment of flexure increase, when excavation of foundation pit arrive substrate when, due to hole side soil body active earth pressure effect, reach bending value mostGreatly, the moment after intermediate support pile 5 converts is up to 164.2kNm, with the calculated value being calculated with positive software for calculation is managed145.05kNm is closer to, illustrate this model test be it is feasible, have certain reference value.

Above-described embodiment is a preferred embodiment of the present invention, be to the content of present invention and its application furtherlyIt is bright, it should not be construed as the present invention and be only applicable to above-described embodiment.All technologies realized based on the principle of the invention and summary of the inventionIt all belongs to the scope of the present invention.

Claims (10)

Translated fromChinese

1.基于地表水渗透的基坑开挖模型试验装置，其特征在于，包括模型箱、基坑支护结构、角钢架、人工湖设计水槽和量测系统；模型箱内设有试验土体、基坑支护结构、角钢架、人工湖设计水槽；1. based on the foundation pit excavation model test device of surface water infiltration, it is characterized in that, comprise model box, foundation pit supporting structure, angle steel frame, artificial lake design water tank and measuring system; , foundation pit support structure, angle steel frame, artificial lake design water tank;所述模型箱为方形箱体；The model box is a square box;所述基坑支护结构通过角钢架与模型箱连接固定；所述基坑支护结构包括若干支护桩、冠梁、腰梁、锚索、锚头、锚固体和喷护面层；多根竖直的支护桩与多根水平的腰梁等间距胶粘固定，多根支护桩的顶端与一根冠梁浇注固定；每相邻两根支护桩之间的腰梁上均打有通孔；所述锚头由螺栓和螺母组成，将每根螺栓穿过腰梁上的每个通孔后，用螺母固定；所有的螺栓杆伸出螺母部分均与锚索连接起来，形成锚索和锚头的连接，用锚固体来包裹锚索的尾端；所述喷护面层包括细铁丝网和混凝土砂浆，在支护桩、冠梁、腰梁、锚头组成的结构表面覆盖细铁丝网并固定，再使用混凝土砂浆抹面，用于模拟基坑的喷护面层；所述喷护面层与锚索不在同一侧；The foundation pit supporting structure is connected and fixed with the model box through the angle steel frame; the foundation pit supporting structure includes several supporting piles, crown beams, waist beams, anchor cables, anchor heads, anchor bodies and spray protection surface layers; A plurality of vertical supporting piles and a plurality of horizontal waist beams are glued and fixed at equal intervals, and the tops of the plurality of supporting piles are fixed by casting with a crown beam; There are through holes; the anchor head is composed of bolts and nuts. After each bolt passes through each through hole on the waist beam, it is fixed with a nut; For the connection between the anchor cable and the anchor head, the tail end of the anchor cable is wrapped with an anchor body; the sprayed protective surface layer includes fine wire mesh and concrete mortar, which is covered on the structural surface composed of supporting piles, crown beams, waist beams and anchor heads. The fine wire mesh is fixed and then plastered with concrete mortar to simulate the sprayed surface layer of the foundation pit; the sprayed surface layer and the anchor cable are not on the same side;所述角钢架为固定而成的门字型件，其上布置监测仪器连接量测系统；The angle steel frame is a fixed door-shaped part, on which a monitoring instrument is arranged to connect the measurement system;所述人工湖设计水槽通过制作模具并浇筑混凝土砂浆制成，再埋置于模型箱内锚索的一侧，与基坑支护结构平行放置并保持一定距离；The artificial lake design water tank is made by making a mold and pouring concrete mortar, and then is embedded in one side of the anchor cable in the model box, and is placed in parallel with the foundation pit support structure and maintains a certain distance;所述量测系统包括应变片、位移计、数据采集仪、电脑和照相机；应变片通过传输线连接数据采集仪；位移计、数据采集仪通过传输线连接电脑；电脑启动相应数据采集软件读取位移计、数据采集仪传输来的数据信息；照相机放置于模型箱外,面对喷护面层的一侧。The measurement system includes a strain gauge, a displacement gauge, a data acquisition instrument, a computer and a camera; the strain gauge is connected to the data acquisition instrument through a transmission line; the displacement gauge and the data acquisition instrument are connected to the computer through the transmission line; the computer starts the corresponding data acquisition software to read the displacement gauge , The data information transmitted by the data acquisition instrument; the camera is placed outside the model box, facing the side of the spray protection surface layer.2.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述的模型箱由透明有机玻璃板组合而成的正方形无盖箱体。2 . The model test device for foundation pit excavation based on surface water infiltration according to claim 1 , wherein the model box is a square box without a cover formed by combining transparent plexiglass plates. 3 .3.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述的角钢架由2根长角钢和1根短角钢焊接而成，2根长角钢的首端之间焊接短角钢，所述的角钢为不锈钢直角角钢。3. the foundation pit excavation model test device based on surface water penetration according to claim 1, is characterized in that, described angle steel frame is welded by 2 long angle steels and 1 short angle steel, and 2 long angle steels are welded. A short angle steel is welded between the head ends, and the angle steel is a stainless steel right angle steel.4.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述支护桩桩顶的竖向位移运用拉线式位移传感器监测，支护桩桩顶水平位移采用激光位移传感器监测。4. The foundation pit excavation model test device based on surface water infiltration according to claim 1, is characterized in that, the vertical displacement of the top of the supporting pile is monitored by a pull-wire displacement sensor, and the top of the supporting pile is horizontal The displacement is monitored using a laser displacement sensor.5.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述应变片通过信号传输线传输到数据采集仪的信号、位移计的信号最终均传输到电脑的相应数据采集软件上，在试验过程中所有信号同步采集。5. The foundation pit excavation model test device based on surface water infiltration according to claim 1, characterized in that, the signal transmitted by the strain gauge to the data acquisition instrument and the signal of the displacement meter through the signal transmission line are finally transmitted to the computer On the corresponding data acquisition software, all signals are collected synchronously during the test.6.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述的数据采集仪、电脑在试验过程中排除干扰，其位置不可挪动。6 . The excavation model test device for foundation pits based on surface water penetration according to claim 1 , wherein the data acquisition instrument and the computer eliminate interference during the test, and their positions cannot be moved. 7 .7.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述的照相机在试验过程中应排除干扰，其位置不可挪动；可根据拍摄需要增设光源。7. The foundation pit excavation model test device based on surface water penetration according to claim 1, wherein the camera should eliminate interference during the test process, and its position cannot be moved; a light source can be added according to shooting needs.8.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述的人工湖设计水槽在试验过程中须始终向水槽中注水保持满水状态。8. The foundation pit excavation model test device based on surface water infiltration according to claim 1, wherein the artificial lake design water tank must always inject water into the water tank to maintain a full water state during the test process.9.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，所述模型箱内填筑的试验土体采用干土作为骨料，容重材料、内摩擦角敏感材料、黏聚力敏感材料分别选取不同填料，通过运用四因素四水平的正交试验设计方法确定模型试验土层与原状土层最为相似的配比进行配置得到。9. The foundation pit excavation model test device based on surface water penetration according to claim 1, wherein the test soil filled in the model box adopts dry soil as aggregate, bulk density material, internal friction angle Different fillers were selected for sensitive materials and cohesion-sensitive materials, respectively, and were configured by using the orthogonal experimental design method of four factors and four levels to determine the most similar ratio between the model test soil layer and the undisturbed soil layer.10.根据权利要求1所述的基于地表水渗透的基坑开挖模型试验装置的使用方法，采用权利要求1所述的基于地表水渗透的基坑开挖模型试验装置，其特征在于，包括如下步骤：10. The method of using the foundation pit excavation model test device based on surface water infiltration according to claim 1, using the foundation pit excavation model test device based on surface water infiltration according to claim 1, it is characterized in that comprising: Follow the steps below:步骤1.将支护桩、冠梁、腰梁、锚索、锚头、喷护面层加工组装成基坑支护结构；在基坑支护结构的支护桩的合理位置粘贴应变片；Step 1. Process and assemble supporting piles, crown beams, waist beams, anchor cables, anchor heads, and spray protection surface layers into foundation pit supporting structures; paste strain gauges at reasonable positions of supporting piles of foundation pit supporting structures;步骤2.将组装好的基坑支护结构通过角钢架与模型箱连接固定；Step 2. Connect and fix the assembled foundation pit support structure with the model box through the angle steel frame;步骤3.向模型箱内分层装填试验土体夯实，每当填筑至各道锚索的相应高度时调整好锚索的位置，并用锚固体包裹锚索的尾部，然后继续装填各层试验土体并夯实；Step 3. Fill the test soil into the model box in layers and compact it, adjust the position of the anchor cables when filling to the corresponding height of each anchor cable, and wrap the tail of the anchor cables with anchors, and then continue to fill each layer for the test. soil and compaction;步骤4.待试验土体将要填筑完成时，将人工湖设计水槽埋置于模型箱内锚索的一侧，与基坑支护结构平行放置并保持一定距离，然后填埋试验土体与人工湖设计水槽表面持平；再向人工湖设计水槽中注水保持满水状态；Step 4. When the test soil is about to be filled, embed the artificial lake design water tank on one side of the anchor cable in the model box, place it parallel to the foundation pit supporting structure and keep a certain distance, and then fill the test soil with the anchor cable. The surface of the artificial lake design tank is flat; then water is injected into the artificial lake design tank to keep it full;步骤5.在模型箱和角钢架上架设位移计，分别监测基坑支护结构的桩顶水平位移和桩顶竖向位移；然后将应变片通过信号传输线与数据采集仪连接起来；再将位移计、数据采集仪通过信号传输线连接到笔记本电脑上，启动相应数据采集软件并做好调试工作；将照相机放置于模型箱外,面对喷护面层的一侧，调节相机参数，设置照相机的自动拍摄时间为间隔20s；若实验室光线不足，可在照相机两侧增设光源；利用电脑采集记录试验初始状态下应变片、位移计的读数，利用照相机拍摄试验初始状态下的试验土体照片；Step 5. Set up displacement gauges on the model box and angle steel frame to monitor the horizontal displacement of the pile top and the vertical displacement of the pile top of the foundation pit supporting structure respectively; then connect the strain gauge with the data acquisition instrument through the signal transmission line; The displacement meter and data acquisition instrument are connected to the laptop computer through the signal transmission line, start the corresponding data acquisition software and do the debugging work; place the camera outside the model box, facing the side of the spray protection layer, adjust the camera parameters, and set the camera The automatic shooting time is at an interval of 20s; if there is insufficient light in the laboratory, light sources can be added on both sides of the camera; use the computer to collect and record the readings of the strain gauges and displacement gauges in the initial state of the test, and use the camera to take photos of the test soil in the initial state of the test. ;步骤6.在照相机面对的一侧进行基坑分工况开挖，并在整个基坑土体开挖过程中保持量测系统正常运转状态，记录相应的数据图像信息，直至基坑开挖完成。Step 6. Excavate the foundation pit in different working conditions on the side facing the camera, and maintain the normal operation of the measurement system during the entire foundation pit soil excavation process, and record the corresponding data and image information until the foundation pit is excavated. Finish.