CN205719795U - Excavation of foundation pit model test apparatus under complicated groundwater environment - Google Patents

Abstract

The utility model discloses the excavation of foundation pit model test apparatus under a kind of complicated groundwater environment.Including model casing, water tank, plane of symmetry gear soil unit, foundation pit supporting construction, pressure-bearing Stilt layer, artesian pressure regulation system and measurement system；Water tank is arranged on the upper right side in model casing；Plane of symmetry gear soil unit is fixed on model casing；Pressure-bearing Stilt layer is arranged on bottom model casing；Artesian pressure regulation system is made up of Miniature water pressure transmitter, plexiglass cylinder device and effusion meter；This utility model can phreatic table and the dynamic change of artesian pressure in Simulation of Excavation Process；Measure Water And Earth Pressures and the deformation dynamically changing foundation ditch under phreatic table and artesian pressure effect, arrange correlation test data and determine the problem such as foundation ditch stress and development of deformation rule, the foundation ditch Study on Problems caused for the complicated groundwater environment such as phreatic table and artesian pressure dynamically change provides effective test data support, and provides foundation for theoretical analysis model afterwards.

Description

Excavation of foundation pit model test apparatus under complicated groundwater environment

Technical field

This utility model relates to a kind of excavation models assay device, particularly relates to phreatic table and artesian pressure dynamically change etc. multiple Excavation of foundation pit model test apparatus under the conditions of miscellaneous groundwater environment, can be used for simulated diving position and time artesian pressure dynamically changes Interaction between bearing course and overlying weak water penetration soil mass of foundation pit, under the conditions of research trends change phreatic table and artesian pressure The Water And Earth Pressures response of foundation ditch and problem on deformation.

Background technology

In strand, riparian area rich groundwater, engineering often faces below aquiclude at the bottom of Deep Foundation Pit and remains at bearing course Situation, due to pressure reduction well dewatering confined water, large-scale rainfall, river flood stages pass by, tide change etc. will cause phreatic table and artesian water Pressure occurrence dynamics changes, thus it is dynamic to affect foundation ditch Water And Earth Pressures, deformation and stability, phreatic table and artesian pressure further Foundation pit deformation that the complicated groundwater environment such as state change causes and destabilization problems be such area deep-foundation pit engineering material risk source it One.

Set soil constitutive model is used compared to the research of economics analysis method and finite element numerical method, calculated latent Water level and artesian pressure dynamically change the soil mass water soil pressure that causes and deformation size and choose and have the biggest depending on calculating parameter Lai Xing；In Practical Project, the more difficult Water And Earth Pressures carried out (being positioned at excavation of foundation pit region) at the bottom of Foundation Pit is monitored in real time, carries out The most similar engineering monitoring data statistic analysis dynamically changes aquiclude at the bottom of the hole caused to obtain phreatic table and artesian pressure The method of deformation rule also be difficult to realize；In view of geotechnical model test under Chang Chongli, do not affect Soil Microstructure, soil particle Size and soil particle interphase interaction relation are consistent with practical situation, can objectively respond between subsoil water and the soil particle of soil mass of foundation pit Interaction, be widely used in consider resistance to shear of soil strain stress relation microexamination.

At present, the relevant geotechnical model test research of traditional groundwater effect, do not consider that in water, the gas entrance test soil body may The unsaturated soil problem caused；Consider constant phreatic table effect excavation models test, have research (Peng Shuquan. sand barricade break Grand thin sight of bad mechanism studies [D]. Tongji University, and 2007.) use thin film to connect retaining wall by the method smearing epoxy resin after corona And model casing, the method can obtain tests excess pore water pressure, soil pressure and foundation pit deformation data in the soil body, but film corona Technique is complex, and when lateral diaphragm wall displacement is bigger, thin film may occur tear or owing to soil particle friction causes breakage in moving process, Test cannot be smoothly completed or carry out repeating test.Consider WATER LEVEL CHANGES impact excavation models test, have research (Sun Wei. The test of coastal region deep basal pit character and theoretical research [D]. Zhejiang University, 2015.) method that uses fixed retaining wall, the method The situation of change of excess pore water pressure in the soil body can only be obtained, it is impossible to obtain soil pressure change accurately and foundation pit deformation data, Larger difference is still suffered from actual base pit engineering response condition under dynamic level of ground water effect；A large amount of simulated groundwater changes Soil test often considers the changed in stages of phreatic table or artesian pressure, generally when every one-level phreatic table or artesian pressure switch Suspend test, therefore can not realize phreatic table or artesian pressure continuously dynamically changes, it is impossible to inquire into phreatic table or pressure-bearing hydraulic pressure The dynamic rate of change of power is to problems such as Water And Earth Pressures response, soil deformation and the stability influences of foundation ditch during excavation.

In excavation models is tested, great majority research completes the foundation ditch stress under operating mode and deformation feelings for every one-level excavation and propping Condition is launched, and does not considers stress and the deformation of foundation ditch foundation ditch during excavation or propping.At the mould considering Excavation Process In type test, research is had to use earth bag (the Azevedo RF.Centrifuge and Analytical of the weight such as unloading equal-volume Modelling of Excavation in Sand.PhD thesis,University of Colorado,Boulder,CO,USA,1983.) Or discharge generation soil liquid (Bolton MD and Powrie W.The collapse of diaphragm walls retaining clay.G é Otechnique, 1987,37 (3): 335-353.) the method simulation soil excavation unloading such as, this type of method can not be opened by accurate simulation foundation ditch Digging the change of stress field in the soil body caused, the foundation ditch stress and the deformation that cause with actual excavation of foundation pit still suffer from certain difference Different.The model test employing pre-plugged of a large amount of simulating excavation installs the method for the retaining wall of support, direct excavation pit The soil body, it is not necessary to carrying out propping operation again, the method is relatively simple, but preset all inner supports all will be at whole digging process Middle stress, it is clear that inconsistent with the foundation ditch stressing conditions of Practical Project, also cannot non-propping in accurate simulation Excavation Process In the case of the stress of foundation ditch and deformation.Research is had to use hydraulic jack to apply the method simulation of power to retaining wall support at present The installation supported, the method uses hydraulic means more complicated, the method inapplicable when excavation of foundation pit width is bigger.The most exhausted The excavation plane of symmetry of most of excavation of foundation pit models is vertical fixing baffle plate, realizes excavation of foundation pit by grabbing downwards soil or soil digging, The method can not excavate soil layer, the soil body that meeting disturbance is not excavated by clear definition；The method is loaded down with trivial details, is difficult to operation, particularly foundation ditch When the size of excavation model is more compared with big or needs excavation the soil body, the workload of test operation is the biggest.Therefore, how to realize The Important Problems being to need in excavation of foundation pit model test to solve is installed in soil excavation and support exactly.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, this utility model provides the excavation of foundation pit model examination under complicated groundwater environment Experiment device, solves the problem of modelling that in test, phreatic table and artesian pressure dynamically change, can simulated diving position and pressure-bearing hydraulic pressure Interaction between subsoil water and soil mass of foundation pit when power dynamically changes, measures phreatic table and the artesian pressure effect of dynamically change The Water And Earth Pressures of lower foundation ditch and deformation, arrange correlation test data and determine foundation ditch when phreatic table and artesian pressure dynamically change The problems such as stress and development of deformation rule, the foundation ditch caused for the complicated groundwater environment such as phreatic table and artesian pressure dynamically change Study on Problems provides effective test data support, and provides foundation for theoretical analysis model afterwards.

This utility model solves its technical problem and be the technical scheme is that the excavation of foundation pit mould under a kind of complicated groundwater environment Type assay device, including model casing, water tank, some planes of symmetry gear soil unit, foundation pit supporting construction, pressure-bearing Stilt layer, pressure-bearing Hydraulic pressure draught control system and seven parts of measurement system；Described model casing by model casing framework, safety glass, model casing base plate, Top frame, reaction plate and model casing base composition；The bottom fixed model box plate of described model casing framework, former and later two sides are solid Determine safety glass；Described model casing framework and reaction plate are each attached on model casing base, and top is connected by top frame；Described mould The bottom right side of molding box installs the second water flowing valve of connection pressure-bearing Stilt layer, regulates system for connection mode molding box and artesian pressure System；

Described water tank by the aluminium sheet of band limbers, bar shaped aluminium sheet, tank bracket, tank bracket fixed screw, rule, first Water flowing valve and first-class gauge composition, the upper right side being erected in model casing by tank bracket, be used for controlling and observing the soil body In SEA LEVEL VARIATION；The surface of aluminum plate of described band limbers pastes anti-filter geotextile, tests the soil body during preventing SEA LEVEL VARIATION Loss；Described rule is pasted onto on safety glass, can be used for directly observing and record SEA LEVEL VARIATION situation；Described first leads to Penstock is arranged on the right side of model casing in order to joining water box and first-class gauge；

Described plane of symmetry gear soil unit is U-shaped stainless steel strip, is bolted on model casing framework；Described U-shaped rustless steel Being connected by H type watertight rubber bar between bar, U-shaped stainless steel strip is connected by S type watertight rubber bar with model casing framework；

Described foundation pit supporting construction includes retaining wall, retaining wall support and some support units；Support is passed through on described retaining wall top Fixing bolt fixed retaining wall support, middle part has screwed hole, by the support needed for screwed hole threaded installation support unit Fixing bolt, the fixing watertight rubber bar of both sides fluting；Described watertight rubber bar ensures to contact with model casing in retaining wall moving process Face does not leaks；One end of described support unit has inner thread mouth, and inner thread mouth is connected with supporting fixing bolt thread, real The installation of existing support unit；

Described pressure-bearing Stilt layer is made up of the corrosion resistant plate of band limbers, rustless steel short column and anti-filter geotextile；Described band water flowing Fix rustless steel short column bottom the corrosion resistant plate in hole, on the model casing base plate being positioned in model casing, and with four sides of model casing Face seal connects；The corrosion resistant plate surface mount anti-filter geotextile of described band limbers；

Described artesian pressure regulation system is made up of Miniature water pressure transmitter, plexiglass cylinder device and second gauge； Described plexiglass cylinder device is made up of plexiglass cylinder, lucite base, graduation mark and T-way water valve door；Described Plexiglass cylinder is fixed on lucite base, and sidewalls vertical arranges graduation mark, and bottom arranges T-way water valve door；Described Miniature water pressure transmitter passes through tee T connection mode molding box and plexiglass cylinder device, and Miniature water pressure transmitter can be remembered continuously The dynamic situation of change of record artesian water；Described plexiglass cylinder is connected with second gauge by T-way water valve door, by the Two effusion meters accurately regulate the change of water-column in plexiglass cylinder thus the dynamic change of artesian water in implementation model case；

Described measurement system includes that miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer, multi-channel data are adopted Collection instrument and digital camera；Described miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer are transmitted by signal Line connecting multi-channel data collecting instrument；Described digital camera is positioned over model casing dead ahead.

Further, described support unit includes solid aluminum bar, expansion link and support connecting bolt；Have on described solid aluminum bar Some grooves, one end has inner thread mouth；Described expansion link is hollow aluminum pipe, and expansion link has some screwed holes；Described Support connecting bolt props up the groove of solid aluminum bar through the screwed hole on expansion link.

Further, described support unit includes the first support bar, the second support bar and sleeve；One end of described first support bar There is external screw thread；One end of described second support bar has inner thread mouth, and the other end has external screw thread；Described sleeve has interior spiral shell Stricture of vagina passage, threaded one end connects the first support bar, threaded second support bar of the other end.

Further, described digital camera answers exclusive PCR in process of the test, and its position can not be moved；Can be according to bat Take the photograph and need to set up light source.

Further, described model casing framework is welded by rustless steel steel bar thick for 10mm and stainless-steel sheet；Described tempering Glass is arranged on inside model casing framework by building glue；Described model casing base plate and reaction plate are the rustless steel steel that 10mm is thick Plate；Described top frame is welded by the rustless steel steel bar that 20mm is thick；Described model casing main body and reaction plate are by surrounding point solid welding Due to model casing base；Described retaining wall is aluminium sheet, and its thickness is obtained by the retaining wall Rigidity Calculation of test simulation；Described gear soil Wall bracket is the strip aluminium sheet that 20mm is thick；Described retaining wall keeps vertical with safety glass in moving process all the time；Described One water flowing valve, the second water flowing valve, T-way water valve door are copper core valve.

Further, the diameter of described solid aluminum bar, the wall thickness of expansion link, the diameter of the first support bar, the second support bar straight The wall thickness of footpath and sleeve is obtained by the Rigidity Calculation of the inner support of test simulation.

Further, according to the foundation model assay device of a kind of dynamic artesian water effect described in claim, it is characterised in that Described miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer and the signal transmssion line of Miniature water pressure transmitter It is connected to same signal sampler, process of the test ensures the synchronous acquisition of all signals.

Further, described water tank and plexiglass cylinder are built with air free water.

Further, the test of the bottom in the model casing soil body is gravelly sand；The overlying test soil body is the weak water penetration soil body.

Further, the described weak water penetration soil body is clay silt；Described gravelly sand and the weak water penetration soil body use air free water saturated.

Compared with prior art, the beneficial effects of the utility model are:

1, this utility model uses the air free water saturation testing soil body before the test, provides depletion of QI artesian water environment, make in process of the test The hole that must test the soil body is full of air free water, has operated as above 2 benefits: one is to avoid underwater bubble to enter weak water penetration soil layer Cause the unsaturation problem (compared with saturated soil, the mechanical characteristic of unsaturated soil exists larger difference and uncertainty) of the soil body； Two is to avoid underwater bubble to disturb miniature pore water pressure sensor to affect its certainty of measurement.

2, the water tank in this utility model is erected in model casing, uses the gap between glass cement sealing radiator and model casing, band The aluminium sheet of limbers makes the water level in water tank connect with test soil body water level, can be by the water in first-class gauge regulating tank Position is with the dynamic change of simulation test soil body phreatic table；Rule on water tank is pasted onto on safety glass, it is simple to directly observation and Record SEA LEVEL VARIATION situation.Second gauge is used accurately to regulate the change amplitude of water-column in plexiglass cylinder device And rate of change, thus the simulation that in implementation model case, artesian water the most dynamically changes；The signal transmission of Miniature water pressure transmitter Line and (be connected and have the same of miniature pore water pressure sensor, miniature soil pressure cell and displacement transducer) multi-channel data acquisition Instrument can record the dynamic situation of change of artesian water continuously after connecting, it is achieved the phreatic table of dynamically change and artesian pressure and ground Water And Earth Pressures, the synchronous monitoring of soil deformation.

On the one hand 3, this utility model uses pressure-bearing Stilt layer can realize from bottom to top the test soil body in abundant saturated model case, has It is beneficial to gas purging in the test soil body；On the other hand connection artesian pressure regulation system is to provide pressure-bearing gravel layer dynamically to change Artesian pressure, close with the mode of occurence of natural artesian water；Pressure-bearing gravel layer water penetration weak with overlying soil layer directly contact by Interaction between bearing course and overlying weak water penetration soil layer in objective simulation dynamic artesian water mechanism, is conducive to further Disclose artesian pressure and dynamically change the response of soil mass of foundation pit Water And Earth Pressures and soil mass of foundation pit deformation rule caused.In water tank belt water flowing The aluminium sheet in hole and the surface mount anti-filter geotextile of the corrosion resistant plate of pressure-bearing Stilt layer band limbers, prevent groundwater change process The loss of the middle test soil body；Often research experiment under gravity condition, does not affect the microstructure of soil mass of foundation pit so that soil particle Size and soil particle interphase interaction relation are consistent with practical situation, are conducive to carrying out and relate to the microcosmic of soil particle interphase interaction and grind Study carefully.

4, this utility model uses water tank and pressure-bearing Stilt layer to simulate phreatic table and the artesian pressure of dynamically change, it is possible to achieve The experimental implementation of following three types:

(1) closing the first water flowing valve (phreatic table is constant) of water tank, regulation second gauge is set with water in machine glass cylinder The rate of change of position is to simulate the rate of change of artesian pressure, and research artesian pressure dynamically changes soil mass of foundation pit Water And Earth Pressures Response, the impact of deformation, the waterline situation shown by water tank graduation mark, know that confined water regime changes foundation ditch phreatic table The impact of change；

(2) waterline in plexiglass cylinder is set in specified altitude assignment (artesian pressure is constant), opens the first water-through valve Door, sets first-class gauge parameter and regulates the rate of change of test soil body phreatic table, and research phreatic table dynamically changes foundation pit earth The response of body Water And Earth Pressures, the impact of deformation, by the artesian pressure situation of change of Miniature water pressure transmitter record, know base Hole phreatic table dynamically changes the impact on artesian pressure change；

(3) parameter setting first-class gauge and second gauge changes to regulate phreatic table and the dynamic of artesian pressure, grinds Study carefully phreatic table and artesian pressure changes jointly on the response of soil mass of foundation pit Water And Earth Pressures, the impact of deformation.

5, this utility model uses dismountable plane of symmetry gear soil unit, the soil body that interim gear passive zone of pit does not excavates, can be Remove plane of symmetry gear soil unit before excavating every layer soil body in advance, carry out excavation of foundation pit by the method unloading soil to the excavation of foundation pit plane of symmetry, Comparing the method that soil digging downward with tradition is fetched earth, this utility model can specify each layer of excavation soil layer not to be affected and does not excavates, operation Convenient, greatly reduce excavation of foundation pit and unload the workload of soil.

6, this utility model can simultaneously simulating excavation and propping operation, obtain excavation of foundation pit and supporting in installation process and drawn The change of the foundation ditch stress field risen, compares and only considers what excavation of foundation pit to a certain degree of depth or propping completed with tradition excavation models test Particular state conducts a research, more comprehensively, reflection excavation of foundation pit and support foundation ditch stress and foundation pit deformation in installation process exactly Response condition；The soil body that foundation ditch will not excavated in inner support installation process by this utility model has disturbing influence；Inner support with It is threadably secured connection between retaining wall, than traditional excavation models test, inner support frame is located on retaining wall or direct Prop up the method that retaining wall realizes propping, more can reflect propping situation when actual base pit engineering excavates objectively；Real by controlling The wall thickness of heart aluminum shank diameter, expansion link wall thickness, the first support bar diameter, the second support bar diameter and sleeve realizes internal support of foundation pit The simulation of rigidity, more objectively reflects the inner support Effects on Engineering to excavation of foundation pit；Can according to the demand of geotechnical model test, Adjust the quantity of inner support element, and the inner support on retaining wall fixes position and the quantity of bolt, opening of the different foundation ditch of simulation Dig situation.

7, this utility model uses retractable supports element, can simulate the excavation of foundation pit test of different in width, compare with traditional Excavation of foundation pit model test uses the support of regular length or retractable supports to be only used for realizing supporting the experimental considerations installed, can Use same set of assay device to carry out the excavation of foundation pit test of many group different in width, decrease the repacking to assay device, save Experimentation cost and modelling time, operation principle is simple, easy to operate, has the biggest practicality.

Accompanying drawing explanation

Excavation of foundation pit model test apparatus side view under the complicated groundwater environment that Fig. 1 (a) supports for using the first kind.

Excavation of foundation pit model test apparatus side view under the complicated groundwater environment that Fig. 1 (b) supports for using Equations of The Second Kind.

The model casing top view that Fig. 2 (a) supports for using the first kind.

The model casing top view that Fig. 2 (b) supports for using Equations of The Second Kind.

Fig. 3 is excavation of foundation pit plane of symmetry schematic diagram.

Fig. 4 is water tank side view.

Fig. 5 (a) is the plane graph of pressure-bearing Stilt layer structure.

Fig. 5 (b) is the side view of pressure-bearing Stilt layer structure.

Fig. 6 is retaining wall schematic diagram.

Fig. 7 (a) is the foundation pit supporting construction schematic diagram that the first kind supports.

Fig. 7 (b) is the foundation pit supporting construction schematic diagram that Equations of The Second Kind supports.

In figure: model casing 1；Model casing framework 1-1；Safety glass 1-2；Model casing base plate 1-3；Top frame 1-4；Reaction plate 1-5； Model casing base 1-6；Water tank 2；Aluminium sheet 2-1 with limbers；Bar shaped aluminium sheet 2-2；Tank bracket 2-3；Tank bracket is fixed Screw 2-4；Rule 2-5；First water flowing valve 2-6；First-class gauge 2-7；Plane of symmetry gear soil unit 3；Fixed symmetrical face The bolt 4 of gear soil unit；Retaining wall 5；Watertight rubber bar 5-1；Retaining wall support 6；Bracket fixing bolt 7；Support unit 8； Solid aluminum bar 8-1；Hollow aluminum bar 8-2；Support connecting bolt 8-3；First support bar 8-4；Second support bar 8-5；Sleeve 8-6； Support fixing bolt 8-7；Pressure-bearing Stilt layer 9；Corrosion resistant plate 9-1 with limbers；Rustless steel short column 9-2；Anti-filter geotextile 9-3；Second water flowing valve 10；Miniature water pressure transmitter 11；Plexiglass cylinder device 12；Plexiglass cylinder 12-1； Lucite base 12-2；Graduation mark 12-3；T-way water valve door 12-4；Second gauge 13；Gravelly sand 14-1；Clay silt 14-2；Air free water 15.

Detailed description of the invention

With embodiment, this utility model is further illustrated below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the excavation of foundation pit model test apparatus under this utility model complexity groundwater environment, including model Case 1, water tank 2, some planes of symmetry gear soil unit 3, foundation pit supporting construction, pressure-bearing Stilt layer 9, artesian pressure regulation system With seven parts of measurement system.

Described model casing 1 is by model casing framework 1-1, safety glass 1-2, model casing base plate 1-3, top frame 1-4, reaction plate 1-5 Form with model casing base 1-6；The bottom fixed model box plate 1-3 of described model casing framework 1-1, former and later two sides are fixed Safety glass 1-2；Described model casing framework 1-1 and reaction plate 1-5 is fixed on, by surrounding spot welding, the model that I-steel is welded On bottom seat 1-6, top is connected by surrounding spot welding by stainless steel top frame 1-4；Described model casing framework 1-1 is by 10mm thickness Rustless steel steel bar and stainless-steel sheet are welded；Described safety glass 1-2 is arranged on model casing framework 1-1 by building glue Inner side；Described model casing base plate 1-3 and reaction plate 1-5 is the stainless-steel sheet that 10mm is thick；Described top frame 1-4 is thick by 20mm Rustless steel steel bar be welded；

Described water tank 2 is by the aluminium sheet 2-1 of the band limbers vertically placed, the steel of laterally disposed bar shaped aluminium sheet 2-2, front and back both sides The inwall changing glass 1-2 and model casing framework 1-1 connects formation by glass cement, is erected at model casing 1 by tank bracket 2-3 Interior upper right side, for the SEA LEVEL VARIATION controlling and observing in the soil body；The aluminium sheet 2-1 and tank bracket 2-3 of described band limbers Connection is tightened by tank bracket fixed screw 2-4；The aluminium sheet 2-1 surface mount anti-filter geotextile of described band limbers, prevents The loss of the soil body is tested during SEA LEVEL VARIATION；Described rule 2-5 be arranged on safety glass 1-2 can be used for directly observing and Record SEA LEVEL VARIATION situation；Described first water flowing valve 2-6 is arranged on the right side of model casing in order to joining water box 2 and first-class gauge 2-7；

Described plane of symmetry gear soil unit 3 is U-shaped stainless steel strip, is fixed on model casing framework 1-1 by bolt 4；Described U Being connected by H type watertight rubber bar between type stainless steel strip, U-shaped stainless steel strip and model casing framework 1-1 are by S type sealing rubber Adhesive tape connects；

Described foundation pit supporting construction includes retaining wall 5, retaining wall support 6 and some support units 8；Described retaining wall 3 is moving During all the time with safety glass 1-2 keep vertical；One end of described support unit 8 has an inner thread mouth, inner thread mouth with Fixing bolt 8-7 is threaded in support, it is achieved the installation of support unit 8；

Described pressure-bearing Stilt layer 9 is made up of the corrosion resistant plate 9-1 of band limbers, rustless steel short column 9-2 and anti-filter geotextile 9-3； The corrosion resistant plate 9-1 of described band limbers is tightly connected by glass cement with model casing framework 1-1, safety glass 1-2；Described band The corrosion resistant plate 9-1 surface mount anti-filter geotextile 9-3 of limbers, prevents from testing in artesian pressure change procedure the stream of the soil body Lose；

The bottom right side of described model casing 1 installs the second water flowing valve 10 of connection pressure-bearing Stilt layer 9, for connection mode molding box 1 System is regulated with artesian pressure；The bottom test soil body in model casing 1 is gravelly sand 14-1, to simulate pressure-bearing soil layer；Overlying is tried Testing the soil body is the weak water penetration soil body, can use clay silt 14-2, uses air free water saturated；

Described artesian pressure regulation system is by Miniature water pressure transmitter 11, plexiglass cylinder device 12 and second gauge 13 compositions；Described plexiglass cylinder device 12 is by plexiglass cylinder 12-1, lucite base 12-2, graduation mark 12-3 Form with T-way water valve door 12-4；Described plexiglass cylinder 12-1 is fixed on lucite base 12-2, sidewalls vertical Arranging graduation mark 12-3, bottom arranges T-way water valve door 12-4；Described Miniature water pressure transmitter 11 is by tee T connection mode Molding box 1 and plexiglass cylinder device 12, Miniature water pressure transmitter 11 can record the dynamic situation of change of artesian water continuously； Described plexiglass cylinder 12-1 is connected with second gauge 13, by second gauge 13 by T-way water valve door 12-4 The accurately change of water-column thus the dynamic change of artesian water in implementation model case 1 in regulation plexiglass cylinder 12-1；Institute State the first water flowing valve 2-6, the second water flowing valve 10, T-way water valve door 12-4 are copper core valve；

Described measurement system includes that miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer, multi-channel data are adopted Collection instrument and digital camera；Described miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer are transmitted by signal Line connecting multi-channel data collecting instrument；Described digital camera is positioned over model casing dead ahead, can need to set up light source according to shooting； Described digital camera answers exclusive PCR in process of the test, and its position can not be moved；Described miniature pore water pressure senses The signal transmssion line of device, miniature soil pressure cell, displacement transducer and Miniature water pressure transmitter 11 is connected to same signals collecting Instrument, ensures the synchronous acquisition of all signals in process of the test.

As it is shown on figure 3, the thickness of described plane of symmetry gear soil unit 3 is 10mm, the spoil that its width can be simulated as required Layer thickness is adjusted；The size of the bolt 4 of described fixed symmetrical face gear soil unit 3 is M8, is fixedly welded on model casing framework On 1-1.

As shown in Figure 4, described water tank 2 is propped up by the aluminium sheet 2-1 of band limbers, bar shaped aluminium sheet 2-2, tank bracket 2-3, water tank Frame fixed screw 2-4, rule 2-5, the first water flowing valve 2-6 and first-class gauge 2-7 composition；The aluminum of described band limbers Plate 2-1 surface is placed with substantial amounts of water flowing circular hole, it is ensured that in process of the test, the water level in water tank connects and one with test soil body water level Cause, to realize being come the SEA LEVEL VARIATION of the Control experiment soil body by the water level in regulating tank.

As shown in Fig. 5 (a), Fig. 5 (b), the corrosion resistant plate 9-1 of described band limbers makes the depletion of QI in pressure-bearing Stilt layer 9 Water and gravelly sand 14-1 bearing course hydraulic communication, it is provided that the artesian pressure of gravelly sand 14-1 bearing course；Described band limbers stainless The arrangement of the thickness of steel plate 9-1, the arrangement of limbers and rustless steel short column 9-2 should meet Force Calculation requirement so that pressure-bearing frame Dead level 9 be enough to bear the weight of the test soil body.

As shown in Figure 6, described retaining wall 5 is aluminium sheet, and its thickness is obtained by the retaining wall Rigidity Calculation of test simulation；Described gear Cob wall support 6 is the strip aluminium sheet that 20mm is thick；Bracket fixing bolt 7 fixed retaining wall support is passed through on described retaining wall 5 top 6, middle part has screwed hole, fixes bolt 8-7 by the support needed for screwed hole threaded installation support unit 8, and both sides are opened Groove fixes watertight rubber bar 5-1；Described watertight rubber bar 5-1 ensures not send out with model casing 1 contact surface in retaining wall 5 moving process Life is leaked；Described bracket fixing bolt 7 and the size supporting fixing bolt 8-7 are M8.

As shown in Fig. 7 (a), Fig. 7 (b), described support is fixed bolt 8-7 and is passed through the screwed hole on retaining wall 5, tightens solid On retaining wall 5.Described support unit 8 can use following two form:

One, described support unit 8 includes solid aluminum bar 8-1, expansion link 8-2 and supports connecting bolt 8-3；Described solid aluminum bar Having some grooves on 8-1, one end has inner thread mouth；Described expansion link 8-2 is hollow aluminum pipe, if having on expansion link 8-2 Dry screwed hole；Described support connecting bolt 8-3 props up the groove of solid aluminum bar 8-1 through the screwed hole on expansion link 8-2 so that Solid aluminum bar 8-1 and expansion link 8-2 compact siro spinning technology, do not slide in process of the test.The diameter of described solid aluminum bar 8-1 and The thickness of hollow aluminum bar 8-2 is calculated by the support stiffness of test simulation；The size of described support connecting bolt 8-3 may select M6。

Two, described support unit 8 includes the first support bar 8-4, the second support bar 8-5 and sleeve 8-6；Described first support bar One end of 8-4 has external screw thread；One end of described second support bar 8-5 has inner thread mouth, and the other end has external screw thread；Described Sleeve 8-6 has female thread passage, and threaded one end connects the first support bar 8-4, the threaded second support bar 8-5 of the other end. The wall thickness of the diameter of described first support bar 8-4, the diameter of the second support bar 8-5 and sleeve 8-6 is by the inner support of test simulation Rigidity Calculation obtains.

Work process of the present utility model is as follows: first retaining wall 5 and retaining wall support 6 are connected by bracket fixing bolt 7 Assemble；Then installing soil pressure cell on retaining wall 5, both sides notch embeds watertight rubber bar 5-1, and at notch and sealing Epoxy resin is smeared in the gap of rubber strip 5-1；The retaining wall 5 assembled is erected in model casing 1 by retaining wall support 6, Ensure that retaining wall 5 is vertical with the safety glass 1-2 of model casing 1 both sides；The plane of symmetry is installed at the plane of symmetry of excavation of foundation pit model Gear soil unit 3, is fixed on model casing framework 1-1 by the bolt 4 of fixed symmetrical face gear soil unit；It is layered in model casing 1 Filling gravelly sand 14-1 compacting, fills to specified altitude assignment；Layering filling clay silt 14-2 compacting, until having banketed, by the Two-way penstock 10 leads to air free water saturation testing soil body gravelly sand 14-1 and clay silt 14-2 with the speed of 50L/ days to model casing 1, Treat that the soil body closes the second water flowing valve 10 after fully saturated；Pore water pressure sensor, the backfill boring soil body are buried in boring underground；? Soil body surface installation position displacement sensor inside and outside retaining wall 5 and foundation ditch, displacement and the soil mass of foundation pit of monitoring retaining wall 5 deforms feelings respectively Condition；

System (the second water flowing valve 10 remains turned-off) is regulated by the second water flowing valve 10 connection mode molding box 1 and artesian pressure, The signal transmssion line of Miniature water pressure transmitter 11 is connected to multi-Channels Data Acquisition, open T-way water valve door 12-4 to Plexiglass cylinder 12-1 injects air free water, flushes with test soil body end face to liquid level, closes T-way water valve door 12-4；According to The phreatic table dynamic rule of design sets the flow parameter of first-class gauge 2-7, thus by first-class gauge 2-7 essence In true ground regulating tank 1, the change of height of water level is with the dynamic change modeling of phreatic table in implementation model case 1；According to holding of design Setting-out Pressure behaviour Changing Pattern sets the flow parameter of second gauge 13, thus is accurately adjusted by second gauge 13 In joint plexiglass cylinder device 12, the change of water-column is with the dynamic change modeling of artesian water in implementation model case 1.

Digital camera is placed in model casing dead ahead (cannot move in process of the test), regulates camera parameter, number is set The automatic shooting time interval of photographing unit is 20s；If laboratory insufficient light, Led light source can be set up in digital camera both sides； Utilize miniature pore water pressure sensor, miniature soil pressure cell and displacement sensing under data collecting instrument acquisition and recording test original state The reading of device, utilizes the test soil body photo under digital camera shooting test original state；

After treating that above-mentioned test preparation completes, open the first water flowing valve 2-6, the second water flowing valve 10 and T-way water valve Door 12-4, and it is held open state in whole soil mass of foundation pit excavation and support installation process；Remove first segment plane of symmetry gear soil single Unit, slowly excavates the soil body on the left of retaining wall 5 by the method unloading soil to the excavation of foundation pit plane of symmetry；It is excavated to first support set Time below meter position, first is installed and supports, fix bolt 8-7 by supporting the female thread of 8 one end with the support on retaining wall 5 Connect, be allowed to hold out against reaction frame 1-5 by adjusting the length supporting 8, complete to support the installation of 8.Complete first and support installation Continue the excavation soil body afterwards, use identical method to install and support, until excavation of foundation pit completes.

In whole excavation of foundation pit process of the test, apply the latent of the corresponding dynamically change of each operating mode of excavation of foundation pit by water tank 2 Water level, applies the artesian pressure of the corresponding dynamically change of each operating mode of excavation of foundation pit by artesian pressure regulation system；Logical Cross miniature pore water pressure sensor, miniature soil pressure cell and displacement transducer in data collecting instrument continuous acquisition record process of the test Reading, shoot in whole process of the test test the photo of soil deformation by triggering digital camera.

By miniature pore water pressure sensor and the reading of miniature soil pressure cell of analytical data Acquisition Instrument acquisition and recording, draw base Cheat phreatic table and artesian pressure in whole digging process and dynamically change the Water And Earth Pressures response pattern caused；Adopted by analytical data Collect the reading of the displacement transducer of instrument record, and the photo captured by logarithmic code photographing unit carries out PIV graphical analysis, obtains unearthed The displacement field of body, thus learn the deformation rule that soil mass of foundation pit dynamically changes with phreatic table and artesian pressure.

Above-described embodiment is a preferred implementation of the present utility model, is further to this utility model content and application thereof Illustrate, should not be construed as this utility model and be only applicable to above-described embodiment.All based on this utility model principle with utility model content The technology realized belongs to scope of the present utility model.

Claims (8)

1. the excavation of foundation pit model test apparatus under a complicated groundwater environment, it is characterized in that, including model casing (1), water tank (2), some planes of symmetry gear soil unit (3), foundation pit supporting construction, pressure-bearing Stilt layer (9), artesian pressure regulation system and seven parts of measurement system；Described model casing (1) is made up of model casing framework (1-1), safety glass (1-2), model casing base plate (1-3), top frame (1-4), reaction plate (1-5) and model casing base (1-6)；Bottom fixed model box plate (1-3) of described model casing framework (1-1), safety glass (1-2) is fixed in former and later two sides；Described model casing framework (1-1) and reaction plate (1-5) are each attached on model casing base (1-6), and top is connected by top frame (1-4)；The bottom right side of described model casing (1) installs connection pressure-bearing Stilt layer (9) and the second water flowing valve (10) of artesian pressure regulation system；

Described water tank (2) is made up of the aluminium sheet (2-1) of band limbers, bar shaped aluminium sheet (2-2), tank bracket (2-3), tank bracket fixed screw (2-4), rule (2-5), the first water flowing valve (2-6) and first-class gauge (2-7), is erected at the upper right side in model casing (1) by tank bracket (2-3)；Aluminium sheet (2-1) the surface mount anti-filter geotextile of described band limbers；Described rule (2-5) is pasted onto on safety glass (1-2)；Described first water flowing valve (2-6) is arranged on the right side of model casing (1) with joining water box (2) and first-class gauge (2-7)；

Described plane of symmetry gear soil unit (3) is U-shaped stainless steel strip, is fixed on model casing framework (1-1) by bolt (4)；Being connected by H type watertight rubber bar between described U-shaped stainless steel strip, U-shaped stainless steel strip is connected by S type watertight rubber bar with model casing framework (1-1)；

Described foundation pit supporting construction includes retaining wall (5), retaining wall support (6) and some support units (8)；Bracket fixing bolt (7) fixed retaining wall support (6) is passed through on described retaining wall (5) top, middle part has screwed hole, bolt (8-7), the fixing watertight rubber bar (5-1) of both sides fluting is fixed by the support needed for screwed hole threaded installation support unit (8)；One end of described support unit (8) has inner thread mouth, and inner thread mouth is threadeded with supporting fixing bolt (8-7)；

Described pressure-bearing Stilt layer (9) is made up of the corrosion resistant plate (9-1) of band limbers, rustless steel short column (9-2) and anti-filter geotextile (9-3)；The fixing rustless steel short column (9-2) in corrosion resistant plate (9-1) bottom of described band limbers, it is positioned on the model casing base plate (1-3) in model casing (1), and is tightly connected with four sides of model casing (1)；Corrosion resistant plate (9-1) surface mount anti-filter geotextile (9-3) of described band limbers；

Described artesian pressure regulation system is made up of Miniature water pressure transmitter (11), plexiglass cylinder device (12) and second gauge (13)；Described plexiglass cylinder device (12) is made up of plexiglass cylinder (12-1), lucite base (12-2), graduation mark (12-3) and T-way water valve door (12-4)；Described plexiglass cylinder (12-1) is fixed on lucite base (12-2), and sidewalls vertical arranges graduation mark (12-3), and bottom arranges T-way water valve door (12-4)；Described Miniature water pressure transmitter (11) passes through tee T connection mode molding box (1) and plexiglass cylinder device (12)；Described plexiglass cylinder (12-1) is connected with second gauge (13) by T-way water valve door (12-4)；

Described measurement system includes miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer, multi-Channels Data Acquisition and digital camera；Described miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer pass through signal transmssion line connecting multi-channel data collecting instrument；Described digital camera is positioned over model casing dead ahead.

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterized in that, described support unit (8) includes solid aluminum bar (8-1), expansion link (8-2) and supports connecting bolt (8-3)；Having some grooves on described solid aluminum bar (8-1), one end has inner thread mouth；Described expansion link (8-2) is hollow aluminum pipe, and expansion link (8-2) has some screwed holes；Described support connecting bolt (8-3) props up the groove of solid aluminum bar (8-1) through the screwed hole on expansion link (8-2).

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterized in that, described support unit (8) includes the first support bar (8-4), the second support bar (8-5) and sleeve (8-6)；One end of described first support bar (8-4) has external screw thread；One end of described second support bar (8-5) has inner thread mouth, and the other end has external screw thread；Described sleeve (8-6) has female thread passage, and threaded one end connects the first support bar (8-4), threaded second support bar of the other end (8-5).

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterised in that described model casing framework (1-1) is welded by rustless steel steel bar thick for 10mm and stainless-steel sheet；Described safety glass (1-2) is arranged on model casing framework (1-1) inner side by building glue；Described model casing base plate (1-3) and reaction plate (1-5) are the stainless-steel sheet that 10mm is thick；Described top frame (1-4) is welded by the rustless steel steel bar that 20mm is thick；Described model casing main body and reaction plate (1-5) are fixed on model casing base (1-6) by surrounding spot welding；Described retaining wall (5) is aluminium sheet；Described retaining wall support (6) is the strip aluminium sheet that 20mm is thick；Described retaining wall (5) keeps vertical with safety glass (1-2) in moving process all the time；Described first water flowing valve (2-6), the second water flowing valve (10), T-way water valve door (12-4) are copper core valve.

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterized in that, the signal transmssion line of described miniature pore water pressure sensor, miniature soil pressure cell, displacement transducer and Miniature water pressure transmitter (11) is connected to same signal sampler.

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterised in that described water tank (2) and plexiglass cylinder (12-1) are built with air free water (15).

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 1, it is characterised in that the bottom test soil body in model casing (1) is gravelly sand (14-1)；The overlying test soil body is the weak water penetration soil body.

Excavation of foundation pit model test apparatus under a kind of complicated groundwater environment the most according to claim 7, it is characterised in that the described weak water penetration soil body is clay silt (14-2).