CN105386474B - Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment - Google Patents
Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment Download PDFInfo
- Publication number
- CN105386474B CN105386474B CN201510695118.5A CN201510695118A CN105386474B CN 105386474 B CN105386474 B CN 105386474B CN 201510695118 A CN201510695118 A CN 201510695118A CN 105386474 B CN105386474 B CN 105386474B
- Authority
- CN
- China
- Prior art keywords
- seepage
- water
- excavation
- leakage
- foundation pit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/30—Circuit design
- G06F30/36—Circuit design at the analogue level
- G06F30/367—Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
Landscapes
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- General Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Bulkheads Adapted To Foundation Construction (AREA)
Abstract
The invention provides a method for determining influences of leakage of a waterproof curtain above a foundation pit excavation face on the surrounding environment. According to the method, the leakage situation of the waterproof curtain is observed according to soil layer information and foundation pit materials, and the leakage area and the actual leakage amount of the leakage position are measured on site; a three-dimensional finite element model is established, a user-defined leakage unit is set at the corresponding position of the model according to the leakage area, and the osmotic coefficient of the leakage position is determined according to the relative relational graph of the leakage amount and the osmotic coefficient in the three-dimensional model; and the osmotic coefficient of the leakage position is set for the user-defined leakage unit, foundation pit excavation and seepage solidification are simulated in sequence, and the foundation pit surrounding underground water level and the ground settling volume caused by leakage of the waterproof curtain above the foundation pit excavation face are finally determined. The method is simple and convenient to popularize and has very high application value. The method is suitable for the problem of the leakage of the waterproof curtain above the foundation pit excavation face.
Description
Technical field
The present invention relates to a kind of method of construction engineering technical field, specifically a kind of to determine excavation of foundation pit face top
The method that water stopping curtain seepage affects on surrounding enviroment.
Background technology
Since 21 century, the development of the underground space is deepened constantly, the building on a large scale of city underground, underground business
The increasing pressure for effectively alleviating aboveground space such as field and underground garage.Along with the exploitation of the underground space, foundation ditch
Engineering is also emerged in multitude, and at present, the base pit engineering that cutting depth reaches 20～30m is more and more, the even up to 40m having with
On, as deep big foundation pit.For deep big foundation pit, now using being widely that method of the well-points dewatering in combination with water-stop curtain is come
Reduce level of ground water in foundation ditch.Wherein, water-stop curtain played gear soil effect in deep pit digging, both, and prevention ground can be played again
The effect of the horizontal seepage flow of lower water, sum it up, water-stop curtain is that deep big foundation pit engineering excavation is smooth and ensure foundation ditch
Periphery does not produce the technological means of excessive deformation because of seepage action of ground water.However, in Practical Project, because of construction technology, construction
The reasons such as technology often such that there is different degrees of seepage in water-stop curtain, if there is the saturation above excavation of foundation pit face in seepage
Sandy soils, serious seepage so as to cause ground it may happen that, there is sedimentation, pipeline failure, construction cracking in quicksand phenomenon
Etc. disaster.For this purpose, determining the method that excavation of foundation pit face top water stopping curtain seepage affects on seepage environment, deep pit monitor is excavated
Have very important significance.
Find through the retrieval to prior art literature, the research to water stopping curtain seepage is concentrated mainly on seepage to underground
In the impact of water level, the seepage of water-stop curtain on the artesian aquifer of excavation of foundation pit face lower section is directed to, existing analysis method is adopted
It is two-dimensional finite element method.As Vilarrasa in 2011《Engineering Geology》On deliver《A
methodology for characterizing the hydraulic effectiveness of an annular low-
permeability barrier》The numerical simulation result of middle utilization two-dimensional finite element method, draws out different water stopping curtain seepages
Drawdown is time dependent under degree judges figure, but it is applied to the situation that water-stop curtain separates completely water-bearing layer.
Pujades in 2012《Engineering Geology》On deliver《Hydraulic characterization of
diaphragm walls for cut and cover tunnelling》Middle utilization two-dimensional finite element method depicts different seepages
Under the conditions of drawdown derivative and time graph of a relation, and propose some analytic sensitivities, can be with by both combinations
The infiltration coefficient of water-stop curtain is calculated, it has the disadvantage the strip footing being only applicable under certain condition.
In fact, the seepage of water-stop curtain belongs to space problem, and two-dimensional finite element method is directed to simplified plane and asks
Topic, not as space problem three-dimensional finite element method it is more realistic, therefore, it is necessary to set up Three-dimension Numerical Model to simulate
Impact of the excavation of foundation pit face top water stopping curtain seepage to surrounding enviroment.But for threedimensional model, according to entity list
Unit, then at the less position of leakage area, need the very little of stress and strain model so that number of grid is on the high side, causes to calculate numerous
It is trivial, or even the convergence for calculating can be affected, cannot finally determine excavation of foundation pit face top water stopping curtain seepage to surrounding enviroment
Affect.
The content of the invention
The present invention is directed to the deficiencies in the prior art, there is provided one kind determines excavation of foundation pit face top water stopping curtain seepage to week
The method that surrounding environment affects, on the basis of soil layer information and foundation ditch data is understood, according to the water stopping curtain seepage situation of observation,
The leakage area and actual seepage quantity of on-site measurement leakage；Three-dimensional finite element model is set up, in the phase of three-dimensional finite element model
Answer position that self-defined seepage unit is set according to leakage area, and with reference to leakage in three-dimensional finite element model and infiltration coefficient
Dependency relation figure determines the infiltration coefficient of leak location；The infiltration coefficient of leak location is arranged to self-defined seepage unit, successively
Simulating excavation, seepage consolidation, it is final to determine underground water around the foundation ditch that excavation of foundation pit face top water stopping curtain seepage causes
Position and ground settlement.
The present invention is achieved by the following technical solutions：
The present invention provides a kind of method for determining that water stopping curtain seepage affects on surrounding enviroment above excavation of foundation pit face, described
Method comprises the steps：
The first step, to foundation ditch site inspection is carried out, and determines soil layer division information and groundwater occurrence situation, and by drilling
Fetching earth carries out laboratory soil test, obtains the physical and mechanical parameter of soil layer；
Second step, obtain foundation ditch planar dimension, cutting depth, and water-stop curtain thickness, buried depth, elastic modelling quantity,
Infiltration coefficient, it is determined that considering the water-stop curtain equivalent elastic modulus E ' of strength degradation effect；
3rd step, observes the leakage scenarios of excavation of foundation pit face top water-stop curtain, records leak location, seepage form, really
Determine leakage area D, actual seepage quantity Q at water stopping curtain seepagek；
4th step, using finite element analysis software the three-dimensional fluid structurecoupling of excavation of foundation pit face top water stopping curtain seepage is set up
Model；According to field investigation, self-defined seepage is set according to leakage area in the corresponding leak location of three-dimensional fluid structure interaction mode
Unit, Simulation of Excavation Process；
5th step, to self-defined seepage unit the osmotic coefficient k of varying number level is assumedj, activation excavation of foundation pit face top
Seepage boundary on the inside of water-stop curtain, determines water-stop curtain seepage seepage for a period of time after (such as 1 day) under each operating mode
Amount Q；
6th step, sets up Descartes's rectangular coordinate system, and transverse axis is the osmotic coefficient k of varying number levelj, the longitudinal axis is leakage
Q, makes leakage Q and osmotic coefficient kjDependency relation figure, and actual seepage quantity Q of on-site measurement is determined according to graph of a relationkIt is right
Answer the osmotic coefficient k of leak location；
7th step, to three-dimensional fluid structure interaction mode in self-defined seepage unit arrange leak location osmotic coefficient k, enter
Row seepage consolidation is simulated, and determines level of ground water and surface subsidence around the foundation ditch that excavation of foundation pit face top water stopping curtain seepage causes
Amount.
Preferably, in the first step, described soil layer is divided and referred to：By the method for boring extracting soil to earth's surface in foundation ditch below
Soil layer in the range of 2.5 times of foundation depths is divided, and subsequently obtaining job site soil sample carries out laboratory soil test, is applied
Work scene soil layer division information and geological information, determine each soil layer soil nature and corresponding the thickness of the layer；
Preferably, in the first step, described groundwater occurrence situation is referred to：Visit water instrument using drilling is carried out to foundation ditch place
Underground water drilling is verified, and by the soil body type for disclosing the type and thickness in water-bearing layer are judged；The steady of different water cut layer is observed in drilling well
Water level is determined, for artesian aquifer takes water proof measure to survey its fixed level behind tested water-bearing layer and other water-bearing layer isolation.
Preferably, in the first step, described boring extracting soil is referred to：The soil at scene is obtained with thin-wall sampler around foundation ditch
Sample, soil sample number is advisable with three test specimens.
Preferably, in the first step, described laboratory soil test is referred to：Density test, specific gravity test, water ratio test,
Triaxial test, conventional Axial compression tests, load test and results of permeability tests.
Preferably, in the first step, described physical and mechanical parameter is referred to：The severe of the soil body, void ratio, effective cohesion intercept,
Internal friction angle, modulus of compressibility, Poisson's ratio, deformation modulus, horizontal-hole blasting and vertical permeability coefficient.
Preferably, in second step, described water-stop curtain equivalent elastic modulus E ' meets below equation：
E '=η Es,
Wherein：η is modulus reduction coefficient, takes 1/5；EsFor the elastic modelling quantity of armored concrete.
Preferably, in second step, described water-stop curtain infiltration coefficient is divided into horizontal direction and vertical direction, horizontal direction
Concrete filtration coefficient is taken with the infiltration coefficient of vertical direction.
Preferably, in the 3rd step, described leak location is referred to：Seepage region whole foundation ditch plane position coordinates,
And the depth size in foundation ditch vertical direction.
Preferably, in the 3rd step, described seepage form is referred to：Underground water Jing water-stop curtains penetrate into what is presented during foundation ditch
Seepage shape.
Preferably, in the 3rd step, leakage area D determines in the following manner at described water stopping curtain seepage：
Range estimation seepage region is located at the Position Approximate of ground surface, and on the ground surface near institute's excavation pit object of reference is chosen
(object of reference has position coordinates on foundation ditch plan), measures the distance in object of reference and seepage region, determines seepage region whole
The position coordinates of individual foundation ditch plane；Lining rope is transferred at the plan-position coordinate in seepage region, seepage region is measured most respectively
Tip depth h1, lowermost end depth h2And the distance between seepage region Liang Ge sides L, obtain leakage area D：
D=L × (h2-h1)。
Preferably, in the 3rd step, described actual seepage quantity QkDetermine in the following manner：
A drum is laid in underface at water stopping curtain seepage above excavation of foundation pit face, measures the basal diameter of drum
The height h of d, bucket3, in bucket water height h4；Leakage Q of 2 hours of on-site measurement leak location2kSize；The Q2kIt is full
Sufficient below equation：
Q2k=NV+ (π d2/4)×h4,
In formula：N is drum volume by meeting within 2 hours the barrelage of percolating water, V；Drum volume V meets below equation：
V=(π d2/4)×h3；
By leakage Q of the 2 of on-site measurement hours2k, estimate actual seepage quantity Q of the seepage after 1 dayk, i.e. Qk=
12Q2k。
Preferably, in the 4th step, described self-defined seepage unit refers to two nodes with certain permeability and rigidity
Solid element conode in line unit, the self-defined seepage unit and threedimensional model, and have three basic parameters：Leakage area
Dz, osmotic coefficient k and elastic modulus E.Specifically, leakage area DzDetermined by leakage area D is surveyed in the 3rd step, meet formula：
Dz=D/n, the grid node that n is passed through by water stopping curtain seepage position in formula；Osmotic coefficient k is by setting varying number level
Osmotic coefficient kjTo determine；Elastic modulus E takes 0.01.
Preferably, in the 4th step, described three-dimensional fluid structure interaction mode is referred to：Model scope centered on foundation ditch, level
Direction is more than dewatering well radius of influence R；It is more than artesian aquifer base plate place depth in model vertical direction；Net is carried out to model
Lattice are divided, and are input into Soil Parameters and water level, and the primary condition and boundary condition of setting model, wherein：Model it is initial
Condition is：Waterline pore pressure is zero, and displacement is zero；Boundary condition is：Model surrounding is constant water level boundary, and bottom is fixed boundary
Condition；The soil body and water-stop curtain adopt 8 node pore pressure units, and contact surface, contact surface friction are arranged between water-stop curtain and the soil body
Coefficient is 0.25.It is highly preferred that empirical equation of the described dewatering well radius of influence R using artesian aquifer：
In formula：S is drawdown (m), and K is the horizontal-hole blasting (m/d) of artesian aquifer.
Preferably, in the 4th step, described Simulation of Excavation Process is referred to：Weaken the foundation ditch inner side soil body, remove foundation ditch
Internal soil body unit completes Base Pit Excavation Simulation, and ground loss rate is adjusted by the weakening degree of the foundation ditch inner side soil body, is controlled
System is within 1%.
Preferably, in the 5th step, the osmotic coefficient k of described varying number leveljTake 10-6m/s、10-5m/s、10-4m/s、
10-3m/s、10-2m/s。
Preferably, in the 5th step, the boundary condition of seepage flow on the inside of described activation excavation of foundation pit face top water-stop curtain is
Refer to：Pore water pressure on the inside of the water-stop curtain of excavation of foundation pit face top is set to into zero.
Preferably, in the 6th step, described actual seepage quantity QkThe osmotic coefficient k of correspondence leak location is in the following manner
It is determined that：
Actual seepage quantity Q is marked on the longitudinal axis of dependency relation figurekPosition, and horizontal line is made, with Q～kjCorrelation is closed
It is that figure intersects at a point, in the point vertical line is made, that is, obtains actual seepage quantity QkThe osmotic coefficient k of correspondence leak location.
Compared with prior art, the invention has the advantages that：
In water stopping curtain seepage model of the present invention above excavation of foundation pit face, self-defined seepage list is arranged to leakage
Unit, solves the difficult problems such as stress and strain model in threedimensional model is difficult, calculating is loaded down with trivial details, finally determines excavation of foundation pit face top sealing curtain
Impact of the curtain seepage to surrounding enviroment.The inventive method is simple, is easy to promote, with very big using value.The present invention is suitable for
In the problem of excavation of foundation pit face top water stopping curtain seepage.
Description of the drawings
Fig. 1 a are the grid partial enlarged drawing of one embodiment of the invention excavation of foundation pit face top water stopping curtain seepage drag；
Fig. 1 b are one embodiment of the invention excavation of foundation pit face top water stopping curtain seepage drag three dimensional network trrellis diagram；
Fig. 2 is the self-defined seepage cell schematics of one embodiment of the invention；
Fig. 3 is leakage Q and k under one embodiment of the invention water stopping curtain seepagejDependency relation figure (after seepage 1 day)；
Fig. 4 is that the first artesian aquifer section I-I ' drawdown figures are (steady under one embodiment of the invention water stopping curtain seepage
It is fixed)；
Fig. 5 is section I-I ' ground fallout plots (100 days) under one embodiment of the invention water stopping curtain seepage.
Specific embodiment
Embodiments of the invention are elaborated below in conjunction with the accompanying drawings：The present embodiment is premised on technical solution of the present invention
Implemented, given detailed embodiment and specific operating process, but protection scope of the present invention is not limited to following realities
Apply example.
Certain base pit engineering is Circular Pit, using high-pressure rotary jet grouting pile as water-stop curtain, the water-bearing layer of foundation ditch present position
System is the water-bearing layer-aquiclude alternating layers of multilayer.In excavation of foundation pit, there is seepage in the water-stop curtain above excavation of foundation pit face
Phenomenon.
The present embodiment provides a kind of method for determining that water stopping curtain seepage affects on surrounding enviroment above excavation of foundation pit face, institute
The method of stating comprises the steps：
The first step, to foundation ditch site inspection is carried out, and determines soil layer division information and groundwater occurrence situation, and by drilling
Fetching earth carries out laboratory soil test, obtains the physical and mechanical parameter of soil layer.
Determine that the soil layer residing for foundation ditch is from top to bottom by boring extracting soil method：
Ground floor is silt, the silty clay that thickness is 14m, belongs to water table aquifer；
The second layer is the silty clay that thickness is 7m, belongs to I aquicludes；
Third layer is the flour sand that thickness is 10m, belongs to I artesian aquifers；
4th layer is that thickness is the silty clay of 5m, belongs to ii aquiclude；
Layer 5 be thickness be 18m silt, ii artesian aquifer；
Layer 6 is the silty clay that thickness is 6m, belongs to ii I aquiclude.
Fetch earth make conventional indoor obtain foundation pit earth layer soil body physico-mechanical properties be：
Ground floor silt, the severe of silty clay are 19.6kN/m3, Poisson's ratio be 0.25, void ratio be 0.80, compression mould
Measure for 6530KPa, internal friction angle be 25 °, horizontal-hole blasting be 6.94 × 10-8M/s, vertical permeability coefficient are 3.47 × 10- 8m/s；
The severe of second layer silty clay is 19.8kN/m3, Poisson's ratio be 0.30, modulus of compressibility be 5410KPa, interior friction
Angle is 21 °, void ratio is that 0.71, horizontal-hole blasting is 2.31 × 10-8M/s, vertical permeability coefficient are 8.10 × 10-9m/s；
The severe of third layer flour sand is 20.4kN/m3, Poisson's ratio be 0.25, void ratio be 0.58, deformation modulus be
16000KPa, internal friction angle are 30 °, effective cohesion intercept is 4.0kPa, horizontal-hole blasting is 4.86 × 10-5M/s, vertical infiltration
Coefficient is 1.74 × 10-5m/s；
The severe of the 4th layer of silty clay is 20.2kN/m3, Poisson's ratio be 0.30, void ratio be 0.72, modulus of compressibility be
6260KPa, internal friction angle are 24 °, horizontal-hole blasting is 1.16 × 10-8M/s, vertical permeability coefficient are 4.64 × 10-9m/s；
The severe of layer 5 silt is 20.3kN/m3, Poisson's ratio be 0.25, void ratio be 0.68, deformation modulus be
12570KPa, internal friction angle are 30 °, effective cohesion intercept is 4.8kPa, horizontal-hole blasting is 2.31 × 10-5M/s, vertical infiltration
Coefficient is 9.26 × 10-6m/s；
The severe of layer 6 silty clay is 20.0kN/m3, Poisson's ratio be 0.30, void ratio be 0.68, modulus of compressibility be
5350KPa, internal friction angle are 22 °, horizontal-hole blasting is 9.29 × 10-9M/s, vertical permeability coefficient are 4.63 × 10-9m/s；
Second step, obtains foundation ditch planar dimension, cutting depth and water-stop curtain thickness, buried depth, elastic modelling quantity, infiltration
Coefficient information, it is determined that considering the water-stop curtain equivalent elastic modulus of strength degradation effect.
The foundation ditch of the present embodiment is Circular Pit, and radius is 18m, and cutting depth is 32m；The thickness of water-stop curtain is
1.2m, depth are 48m, severe is 25kN/m3, horizontal-hole blasting be 1.0 × 10-9M/s, vertical permeability coefficient are 1.0 × 10- 9m/s.The water-stop curtain equivalent elastic modulus E ' for considering strength degradation effect meets below equation：
E '=η Es,
Wherein：η is modulus reduction coefficient, takes 1/5；EsFor the elastic modelling quantity of armored concrete, obtaining its value is：
3rd step, observes the leakage scenarios of excavation of foundation pit face top water-stop curtain, in whole foundation ditch plane, leak location A
(as shown in Figure 1a) on the water-stop curtain madial wall in 45 ° of foundation ditch center east by north direction, and seepage form is in vertical wire
Seepage；By transferring lining rope, tip depth h of leakage is measured1=21m, bottom depth h2=24m, seepage region Liang Ge sides
The distance between L=5cm, therefore leakage area D=0.15m2；Actual seepage quantity QkDetermine in the following manner：
A basal diameter d is laid for 1m in underface at water stopping curtain seepage above excavation of foundation pit face, the height of bucket
h3For the drum of 1.5m, leakage Q of 2 hours of on-site measurement leak location2kSize, after 2 hours in bucket water height h4
For 1.046m, wherein, Q2kMeet below equation：
In formula：N is drum volume by meeting within 2 hours the barrelage of percolating water, as 1, V, and V meets below equation：
V=(π d2/4)×h3=(π × 12/ 4) × 1.5=1.1781m3。
By leakage Q of the 2 of on-site measurement hours2k, estimate actual seepage quantity Q of the seepage after 1 dayk, i.e.,：
Qk=12Q2k=12 × 1.9996=23.9952m3。
4th step, using finite element analysis software the three-dimensional fluid structurecoupling of excavation of foundation pit face top water stopping curtain seepage is set up
Model；According to field investigation, self-defined seepage is set according to leakage area in the corresponding leak location of three-dimensional fluid structure interaction mode
Unit, Simulation of Excavation Process.
Determine dewatering well radius of influence R, in the present embodiment, I artesian aquifers infiltration coefficient is 4.86 × 10-5M/s, i.e.,
4.2m/d, in Excavation Process in foundation ditch I artesian aquifers water level 1m under excavation of foundation pit face, i.e. pressure water head for-
25m, the initial pressure water head of this engineering is -1m, therefore drawdown is 24m, and dewatering well radius of influence R is：
Centered on foundation ditch, horizontal direction is more than dewatering well radius of influence 492m to analysis model, to external expansion 500m, to disappear
Except impact of the boundary condition to result of calculation；In the plane, research range is 1000 × 1000m2；On vertical, depth is calculated
For 60m.In the horizontal direction, finite element grid is outside from dense to sparse by foundation ditch, and 2920 nodes, 2829 lists are contained per layer plane
Unit；In vertical direction, 17 layers are divided into.Whole model has 54720 nodes, 48093 units.
Excavation of foundation pit face top water stopping curtain seepage drag grid partial enlarged drawing as shown in Figure 1 a, 1 b, three-dimensional
Grid chart.Input Soil Parameters and water level, and the primary condition and boundary condition of setting model.Wherein：
The primary condition of model is：Each water-bearing layer initial water level is subsurface 1m in analysis model, and waterline pore pressure is zero,
Displacement is zero；
Boundary condition is：Model surrounding is constant water level boundary, and bottom is fixed boundary condition.
The soil body and water-stop curtain adopt 8 node pore pressure units, and contact surface is arranged between water-stop curtain and the soil body, and contact surface rubs
It is 0.25 to wipe coefficient.
According to field investigation, self-defined seepage unit is set in the corresponding leak location A (as shown in Figure 1a) of analysis model,
Leak location arranges 3 self-defined seepage units, leakage area D altogether through 3 nodesz=D/n=0.15/3=0.05m2,
Fig. 2 is self-defined seepage cell schematics.
In the present embodiment, described Simulation of Excavation Process is referred to：Weaken the foundation ditch inner side soil body, remove foundation ditch inside soil
Body unit completes Base Pit Excavation Simulation, and ground loss rate is adjusted by the weakening degree of the foundation ditch inner side soil body, is controlled 1%
Within.
5th step, to self-defined seepage unit the osmotic coefficient k of varying number level is assumedj, activation excavation of foundation pit face top
Seepage boundary on the inside of water-stop curtain, determines that seepage is after 1 day at water stopping curtain seepage of each operating mode above excavation of foundation pit face
Leakage Q.
The osmotic coefficient k of the varying number level described in the present embodimentjIt is taken as 10-6m/s、10-5m/s、10-4m/s、10-3m/
s、10-2m/s。
The boundary condition of seepage flow on the inside of the water-stop curtain of activation excavation of foundation pit face top described in the present embodiment is referred to：By base
Pore water pressure on the inside of the water-stop curtain of hole excavation face top is set to zero.
6th step, sets up Descartes's rectangular coordinate system, and transverse axis is the osmotic coefficient k of varying number levelj, the longitudinal axis is leakage
Q, makes leakage Q and osmotic coefficient kjDependency relation figure (as shown in Figure 3), according to actual seepage quantity Q of on-site measurementk=
23.9952m3, the point is found on the longitudinal axis of dependency relation figure, and make horizontal line, the horizontal line and dependency relation figure intersection point pair
The abscissa answered is the osmotic coefficient k of leak location：
K=1.0 × 10-5m/s。
7th step, to three-dimensional fluid structure interaction mode in self-defined seepage unit arrange leak location osmotic coefficient k=
1.0×10-5M/s, carries out seepage consolidation simulation, finally show that wire is oozed at the water stopping curtain seepage position A of excavation of foundation pit face top
Leak down I artesian aquifers section I-I ' drawdown figures (stable) (as shown in Figure 4), section I-I ' ground fallout plots (100
My god) (as shown in Figure 5).
The present embodiment can accurately determine impact of the excavation of foundation pit face top water stopping curtain seepage to surrounding enviroment, finally
Level of ground water and ground settlement around at the water stopping curtain seepage of excavation of foundation pit face top is drawn, is compared and is focused only on seepage pair
The research of level of ground water seem more comprehensively, it is more scientific, more reliable.
The specific embodiment of the present invention is described above.It is to be appreciated that the invention is not limited in above-mentioned
Particular implementation, those skilled in the art can within the scope of the claims make various modifications or modification, this not shadow
Ring the flesh and blood of the present invention.
Claims (11)
1. it is a kind of to determine the method that excavation of foundation pit face top water stopping curtain seepage affects on surrounding enviroment, it is characterised in that described
Method comprises the steps：
The first step, to foundation ditch site inspection is carried out, and determines soil layer division information and groundwater occurrence situation, and by boring extracting soil
Laboratory soil test is carried out, the physical and mechanical parameter of soil layer is obtained；
Second step, obtains foundation ditch planar dimension, cutting depth, and water-stop curtain thickness, buried depth, elastic modelling quantity, infiltration
Coefficient, it is determined that considering the water-stop curtain equivalent elastic modulus E ' of strength degradation effect；
3rd step, observes the leakage scenarios of excavation of foundation pit face top water-stop curtain, record leak location, seepage form, it is determined that only
Leakage area D, actual seepage quantity Q at water curtain seepagek；
4th step, using finite element analysis software the solid coupled mode of three-dimensional flow of excavation of foundation pit face top water stopping curtain seepage is set up
Type；According to field investigation, self-defined seepage list is set according to leakage area in the corresponding leak location of three-dimensional fluid structure interaction mode
Unit, Simulation of Excavation Process；
Described self-defined seepage unit refers to the two nodal line units with certain permeability and rigidity, the self-defined seepage list
Solid element conode in unit and threedimensional model, and have three basic parameters：Leakage area Dz, leak location infiltration coefficient
K and elastic modulus E；Wherein：Leakage area DzDetermined by the leakage area D surveyed in the 3rd step, meet formula：Dz=D/n, formula
The grid node that middle n is passed through by water stopping curtain seepage position；The osmotic coefficient k of leak location is by setting varying number level
Osmotic coefficient kjTo determine；
5th step, to self-defined seepage unit the osmotic coefficient k of varying number level is assumedj, activation excavation of foundation pit face top sealing curtain
Curtain on the inside of seepage boundary, determine water-stop curtain under each operating mode seepage for a period of time after leakage Q；
6th step, sets up Descartes's rectangular coordinate system, and transverse axis is the osmotic coefficient k of varying number levelj, the longitudinal axis is leakage Q, is made
Go out leakage Q and osmotic coefficient kjDependency relation figure, and actual seepage quantity Q of on-site measurement is determined according to graph of a relationkCorrespondence is oozed
The osmotic coefficient k of leakage position；
7th step, to three-dimensional fluid structure interaction mode in self-defined seepage unit arrange leak location osmotic coefficient k, oozed
Stream consolidation simulation, determines level of ground water and ground settlement around the foundation ditch that excavation of foundation pit face top water stopping curtain seepage causes.
2. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in the first step：
Described soil layer is divided and referred to：By the method for boring extracting soil to 2.5 times of foundation depths below earth's surface in foundation ditch in the range of
Soil layer divided, subsequently obtaining job site soil sample carries out laboratory soil test, obtains job site soil layer division information
And geological information, determine each soil layer soil nature and corresponding the thickness of the layer；
Described groundwater occurrence situation is referred to：Water instrument is visited using drilling underground water drilling is carried out to foundation ditch place and verified, by taking off
The soil body type of dew judges the type and thickness in water-bearing layer；The fixed level of different water cut layer is observed in drilling well, aqueous for pressure-bearing
Layer takes water proof measure to survey its fixed level behind tested water-bearing layer and other water-bearing layer isolation.
3. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in second step, described water-stop curtain equivalent elastic modulus E ' meets below equation：
E '=η Es,
Wherein：η is modulus reduction coefficient, takes 1/5；EsFor the elastic modelling quantity of armored concrete.
4. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in second step, described water-stop curtain infiltration coefficient is divided into horizontal direction and vertical direction, horizontal direction
Concrete filtration coefficient is taken with the infiltration coefficient of vertical direction.
5. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in the 3rd step：
Described leak location is referred to：Seepage region whole foundation ditch plane position coordinates, and in foundation ditch vertical direction
Depth size；
Described seepage form is referred to：Underground water Jing water-stop curtains penetrate into the seepage shape presented during foundation ditch.
6. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in the 3rd step, leakage area D determines in the following manner at described water stopping curtain seepage：
Range estimation seepage region is located at the Position Approximate of ground surface, and on the ground surface near institute's excavation pit object of reference is chosen, and joins
There is position coordinates on foundation ditch plan according to thing, measure the distance in object of reference and seepage region, determine seepage region in whole base
The position coordinates of hole plane；Lining rope is transferred at the plan-position coordinate in seepage region, seepage region top depth is measured respectively
Degree h1, lowermost end depth h2And the distance between seepage region Liang Ge sides L, obtain leakage area D：
D=L × (h2-h1)。
7. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in the 3rd step, described actual seepage quantity QkDetermine in the following manner：
A drum is laid in underface at water stopping curtain seepage above excavation of foundation pit face, measures basal diameter d, the bucket of drum
Height h3, in bucket water height h4；Leakage Q of 2 hours of on-site measurement leak location2kSize；The Q2kMeet with
Lower formula：
Q2k=NV+ (π d2/4)×h4,
In formula：N is drum volume by meeting within 2 hours the barrelage of percolating water, V；Drum volume V meets below equation：
V=(π d2/4)×h3；
By leakage Q of the 2 of on-site measurement hours2k, estimate actual seepage quantity Q of the seepage after 1 dayk, i.e. Qk=12Q2k。
8. the side that a kind of determination excavation of foundation pit face top according to claim 1 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that in the 4th step：Elastic modulus E takes 0.01；
Described three-dimensional fluid structure interaction mode is referred to：Centered on foundation ditch, horizontal direction affects half to model scope more than dewatering well
Footpath R；Model vertical direction is more than artesian aquifer base plate place depth；Carry out stress and strain model to model, input Soil Parameters and
Water level, and the primary condition and boundary condition of setting model, wherein：The primary condition of model is：Waterline pore pressure is zero,
Displacement is zero；Boundary condition is：Model surrounding is constant water level boundary, and bottom is fixed boundary condition；The soil body and water-stop curtain are equal
Using 8 node pore pressure units, contact surface is set between water-stop curtain and the soil body；
Described Simulation of Excavation Process is referred to：Weaken the foundation ditch inner side soil body, remove foundation ditch inside soil body unit and complete foundation ditch
Excavation simulation, ground loss rate is adjusted by the weakening degree of the foundation ditch inner side soil body, is controlled within 1%.
9. the side that a kind of determination excavation of foundation pit face top according to claim 8 water stopping curtain seepage affects on surrounding enviroment
Method, it is characterised in that described dewatering well radius of influence R adopts the empirical equation of artesian aquifer：
In formula：S is drawdown (m), and K is the horizontal-hole blasting (m/d) of artesian aquifer；
The contact surface coefficient of friction is 0.25.
10. a kind of determination excavation of foundation pit face top water stopping curtain seepage according to any one of claim 1-9 is to peripheral ring
The method that border affects, it is characterised in that in the 5th step：
The osmotic coefficient k of described varying number leveljTake 10-6m/s、10-5m/s、10-4m/s、10-3m/s、10-2m/s；
The boundary condition of seepage flow on the inside of described activation excavation of foundation pit face top water-stop curtain is referred to：Excavation of foundation pit face top is stopped
Pore water pressure on the inside of water curtain is set to zero.
A kind of 11. determination excavation of foundation pit face top water stopping curtain seepages according to any one of claim 1-9 are to peripheral ring
The method that border affects, it is characterised in that in the 6th step, described actual seepage quantity QkThe osmotic coefficient k of correspondence leak location leads to
Cross in the following manner determination：
Actual seepage quantity Q is marked on the longitudinal axis of dependency relation figurekPosition, and horizontal line is made, with Q～kjDependency relation figure
Intersect at a point, in the point vertical line is made, that is, obtain actual seepage quantity QkThe osmotic coefficient k of correspondence leak location.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510695118.5A CN105386474B (en) | 2015-10-22 | 2015-10-22 | Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510695118.5A CN105386474B (en) | 2015-10-22 | 2015-10-22 | Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105386474A CN105386474A (en) | 2016-03-09 |
| CN105386474B true CN105386474B (en) | 2017-05-10 |
Family
ID=55419207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510695118.5A Expired - Fee Related CN105386474B (en) | 2015-10-22 | 2015-10-22 | Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105386474B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107808414B (en) * | 2017-11-02 | 2021-02-26 | 重庆市勘测院 | Method for excavating virtual foundation pit with three-dimensional integration of ground and underground |
| CN108153988B (en) * | 2018-01-09 | 2021-02-09 | 中南大学 | Method for determining design parameters of deep horizontal water-stop curtain of foundation pit of strongly permeable stratum |
| CN110321577B (en) * | 2018-03-30 | 2021-11-16 | 北京交通大学 | Method for calculating settlement of surface outside foundation pit caused by incomplete well precipitation in foundation pit of confined water stratum |
| CN109614654B (en) * | 2018-11-13 | 2022-11-01 | 烟台大学 | Method for accurately acquiring influence radius of foundation pit dewatering well |
| CN110263366B (en) * | 2019-05-07 | 2020-08-21 | 上海交通大学 | Method for determining depth of suspended waterproof curtain inserted into precipitation aquifer |
| CN110763400B (en) * | 2019-09-16 | 2021-08-27 | 光大环保(盐城)固废处置有限公司 | Method and system for detecting defects of vertical impervious curtain |
| CN112597673B (en) * | 2020-12-03 | 2022-05-17 | 上海交通大学 | Method for determining effect of servo support system on foundation pit deformation control under rainfall condition |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003330974A (en) * | 2002-05-10 | 2003-11-21 | Tateishi Kozo Sekkei:Kk | Structure calculating device for building, computer program and recording media |
| CN101845815A (en) * | 2010-05-31 | 2010-09-29 | 同济大学 | Method for calculating and processing uprush plastic failures of confined water foundation pits of soft soil strata |
| CN102002962A (en) * | 2010-11-01 | 2011-04-06 | 华北有色工程勘察院有限公司 | Determining method for water-plugging curtain permeability inversion analysis construction |
| CN102322078A (en) * | 2011-06-17 | 2012-01-18 | 同济大学 | Method for calculating and processing inrushing destruction of excavation and depressurization coupling effect of foundation pit with confined water |
| CN102866983A (en) * | 2012-08-09 | 2013-01-09 | 同济大学 | Finite difference method of fine simulation tubular well structure |
| CN104727289A (en) * | 2015-01-28 | 2015-06-24 | 中铁十六局集团北京轨道交通工程建设有限公司 | Construction method for controlling multiple water-bearing strata to achieve leaking recharge and to protect ambient environment |
-
2015
- 2015-10-22 CN CN201510695118.5A patent/CN105386474B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003330974A (en) * | 2002-05-10 | 2003-11-21 | Tateishi Kozo Sekkei:Kk | Structure calculating device for building, computer program and recording media |
| CN101845815A (en) * | 2010-05-31 | 2010-09-29 | 同济大学 | Method for calculating and processing uprush plastic failures of confined water foundation pits of soft soil strata |
| CN102002962A (en) * | 2010-11-01 | 2011-04-06 | 华北有色工程勘察院有限公司 | Determining method for water-plugging curtain permeability inversion analysis construction |
| CN102322078A (en) * | 2011-06-17 | 2012-01-18 | 同济大学 | Method for calculating and processing inrushing destruction of excavation and depressurization coupling effect of foundation pit with confined water |
| CN102866983A (en) * | 2012-08-09 | 2013-01-09 | 同济大学 | Finite difference method of fine simulation tubular well structure |
| CN104727289A (en) * | 2015-01-28 | 2015-06-24 | 中铁十六局集团北京轨道交通工程建设有限公司 | Construction method for controlling multiple water-bearing strata to achieve leaking recharge and to protect ambient environment |
Non-Patent Citations (3)
| Title |
|---|
| 三维水-土耦合模型在深基坑降水计算中的应用;冯晓腊等;《岩土力学与工程学报》;20050430;第24卷(第7期);第1196-1201页 * |
| 基坑开挖工程中渗流场的三维有限元分析;姜忻良等;《岩土工程学报》;20060531;第28卷(第5期);第564-568页 * |
| 深基坑降水与地面沉降变形三维耦合数值模拟;骆祖江等;《江苏大学学报（自然科学版）》;20060731;第27卷(第4期);第356-359页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105386474A (en) | 2016-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105386474B (en) | Method for determining influences of leakage of waterproof curtain above foundation pit excavation face on surrounding environment | |
| CN105239611B (en) | Determine the method that water stopping curtain seepage influences on surrounding enviroment below excavation of foundation pit face | |
| CN110221357B (en) | Large-span shallow-buried limestone goaf comprehensive exploration method | |
| Wu et al. | Identification of tunnel settlement caused by land subsidence in soft deposit of Shanghai | |
| Peng et al. | Field measurements and finite-element method simulation of a tunnel shaft constructed by pneumatic caisson method in Shanghai soft ground | |
| Chou et al. | Centrifuge modeling of seismically induced uplift for the BART transbay tube | |
| Zhang et al. | Ground and tunnel responses induced by partial leakage in saturated clay with anisotropic permeability | |
| Migliazza et al. | Comparison of analytical method, 3D finite element model with experimental subsidence measurements resulting from the extension of the Milan underground | |
| Wang et al. | Field experiment and numerical simulation of coupling non-Darcy flow caused by curtain and pumping well in foundation pit dewatering | |
| CN102912780B (en) | Sandy soil water-immersion testing method for loess collapsible deformation | |
| di Santolo et al. | Analysis of sinkhole triggering mechanisms in the hinterland of Naples (southern Italy) | |
| Sun et al. | Two underground pedestrian passages using pipe jacking: case study | |
| CN105137488B (en) | Ground water field based on artificial fluid injection describes method | |
| Xu et al. | Evaluation of allowable withdrawn volume of groundwater based on observed data | |
| Zhang et al. | Prediction of water inflow in Tsingtao subsea tunnel based on the superposition principle | |
| Huang et al. | The external water pressure on a deep buried tunnel in fractured rock | |
| CN105257318B (en) | A kind of lining cutting localized seepage causes the method for security protection that tunnel structure is deformed | |
| Wang | Empirical evidence for estimation of subsurface settlement caused by tunneling in sand | |
| Li et al. | The development of sand erosion induced by shield-tunnel joint leakage | |
| CN104123433A (en) | Method for determining soil deformation caused by high-pressure horizontal rotary jet grouting construction | |
| CN105386430B (en) | A kind of lower water-stop curtain both sides water level method for determining difference of water-stop curtain effect | |
| Ong et al. | Ground and groundwater responses due to shaft excavation in organic soils | |
| Lan et al. | New design equation for maximum allowable mud pressure in sand during horizontal Directional drilling | |
| Kabir et al. | Numerical Analyses of the Karnaphuli River Tunnel | |
| Yuan et al. | Analytical approaches of the long-term behavior of a shield tunnel in soft deposit due to groundwater leakage: A review |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170510 Termination date: 20211022 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |