CN107059956A - A kind of brief test method for determining the long-term shear strength of pile-soil interface - Google Patents
A kind of brief test method for determining the long-term shear strength of pile-soil interface Download PDFInfo
- Publication number
- CN107059956A CN107059956A CN201710286569.2A CN201710286569A CN107059956A CN 107059956 A CN107059956 A CN 107059956A CN 201710286569 A CN201710286569 A CN 201710286569A CN 107059956 A CN107059956 A CN 107059956A
- Authority
- CN
- China
- Prior art keywords
- soil
- sample
- long
- pile
- stress
- 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.)
- Granted
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
Abstract
The invention belongs to Geotechnical Engineering field, in particular it relates to a kind of brief test method for determining the long-term shear strength of pile-soil interface.The brief test method of the long-term shear strength of pile-soil interface, is comprised the following steps that：(1), prepared by concrete sample；(2) soil sample, soil sample consolidation, are made；(3) soil sample physico-mechanical properties, is determined；(4), soil sample and concrete sample are combined；(5), composite sample carries out the ordinary triaxial test under different confined pressures, obtains short-term shear strength；(6), composite sample carries out creep triaxial test during long under different confined pressures, monitors long-term shear strain；(7) stress-strain diagram method analyzes the long-term shear strength of pile-soil interface under different confined pressures when, passing through etc..The present invention can simulate the long-term shear strength of pile-soil interface in Practical Project, have a wide range of application, and can directly be completed using quiet triaxial apparatus, simple to operate.
Description
Technical field
It is specifically a kind of to be related to the letter for determining the long-term shear strength of pile-soil interface the invention belongs to Geotechnical Engineering field
Easy test method.
Background technology
Pile foundation was a kind of ancient foundation pattern, by the development of thousands of years, either pile foundation material and stake type, still
Construction method has huge development, it has also become the main foundation pattern such as building, bridge.And the long-time stability of pile foundation
It is most important for engineering safety.In fact, when pile-end soil is that non-closely knit sandy soil or silt and borehole cleaning do not remain loosened soil only
When, under load action, easily occur punching failure.Now, end resistance very little, pile side resistance is larger.Therefore, in certain work
Under the conditions of journey, the problem of research long-term shear strength of pile-soil interface is one particularly significant.
Laboratory test research method at present both at home and abroad for pile-soil interface shear strength is more single, is based on mostly
The direct shear test that boxshear apparatus is carried out, seldom considers the influence of its time effect.Due to the stake in Practical Project side friction with
The time gradually to decay, it is, thus, sought for a kind of experiment of the consideration draw higher with actual condition degree of fitting is entered
The research of the long-term shear strength of row pile-soil interface.
Therefore, the present invention provides a kind of brief test method for determining the long-term shear strength of pile-soil interface.This method is led to
Conventional static triarial test machine is crossed, using the native composite sample of stake, the long-term shearing test of pile-soil interface is carried out, obtains stake soil and connect
The long-term shear strength parameters value of contacting surface, is expected to borrow to destroying offer caused by Practical Project Lateral shearing friction Lack of support
Mirror.
The present Research of the long-term shear strength research method of domestic related pile-soil interface is as follows at present：
1、《Soil and the shearing test research of piles with different side surface roughness exposure face》One text describes one kind and utilizes direct shear apparatus
Carry out research Pile Soil between side-friction force Experimental Method in Laboratory (referring to《Structural engineer》3rd phase in 2011, author：Zhang Ji
Suitable, Hua Bin), in this text, the large-sized multifunction interface shearing instrument that make use of Tongji University to develop, to District of Shanghai cohesive soil with
Interphase interaction and mechanical characteristic with different surface roughness concrete surface have carried out experimental study, but ignore herein
Under the load long term, the influence that soil sample interacts with concrete surface；
2、《The model investigation of interaction between pile and soil influence》One text describes one kind and studied by live large-scale experiment
Between Pile Soil side-friction force method (referring to《Rock-soil mechanics》6th phase in 2008, author：Wang Tao), by the way that model is tried in this text
Test, the result of field measurement and Solution of Elasticity Theory are contrasted, it is indicated that Solution of Elasticity Theory exaggerates stake-stake, Pile Soil, soil-soil phase
Interaction influences, and causes settlement calculation value bigger than normal and the too high inhomogeneities for estimating Pile top force, and propose to Solution of Elasticity Theory
The approaches and methods being modified.The sample yardstick of this method is larger, costly；
3、《Preliminary study on soil-pile interaction under multidirectional horizontal loading》One text describes one kind and utilizes centrifuge direction vibration platform
Unidirectional and direction vibration experiment the method for progress multi-column pier foundation model level (referring to《Rock-soil mechanics》3rd phase in 2008, author：
Su Dong, Li Xiangsong), method for testing requires higher to test apparatus, it is difficult to promote；
4、《The experimental study of Pile Soil sliding friction》One text describes the indoor direct shear test carried out on improved instrument
(referring to《Rock-soil mechanics》4th phase in 2002, author：Zhang Mingyi, Deng Anfu), the test method of this experiment is simple, but experiment mould
Type differs larger with realistic model.
The content of the invention
To overcome the shortcomings of that existing Experimental Method in Laboratory is less, the present invention provides a kind of pile-soil interface that determines and sheared for a long time
The brief test method of intensity.
To achieve the above object, the present invention uses following technical proposals：
A kind of brief test method for determining the long-term shear strength of pile-soil interface, step is as follows：
(1), prepared by concrete sample；
(2) soil sample, soil sample consolidation, are made；
(3) soil sample physico-mechanical properties, is determined；
(4), soil sample and concrete sample are combined；
(5), composite sample carries out the ordinary triaxial test under different confined pressures, obtains short-term shear strength；
(6), composite sample carries out creep triaxial test during long under different confined pressures, monitors long-term shear strain；
(7) stress-strain diagram method analyzes the long-term shear strength of pile-soil interface under different confined pressures when, passing through etc..
Relative to prior art, the present invention has the advantages that：
1st, the present invention can simulate the long-term shear strength of pile-soil interface in Practical Project, have a wide range of application；
2nd, the present invention can directly be completed using quiet triaxial apparatus, simple to operate.
Brief description of the drawings
Fig. 1 is the long-term shear strength brief test method flow schematic diagram of pile-soil interface；
Fig. 2 is test model schematic diagram；
Fig. 3 is that long-term strength determines method schematic diagram；
Fig. 4 is each alphabetical connotation schematic diagram in test model；
Embodiment
As shown in figure 1, a kind of brief test method for determining the long-term shear strength of pile-soil interface, step is as follows：
1st, prepared by concrete sample, and specific method is as follows：
Using mould, a diameter of 60mm is prepared, is highly two pieces of 50mm semicylinders concrete sample, intensity of sample etc.
Parameter of the parameter with reference to pile body in Practical Project.
2nd, soil sample is made, soil sample consolidation, specific method is as follows：
Engineering site is fetched earth, and a diameter of 60mm is prepared using mould, highly for 120mm cylinder initial soil sample；
Initial soil sample is consolidated using quiet triaxial apparatus, discharging consolidation is used when being consolidated, applies certain confined pressure,
Consolidation time is 7 days.The soil sample of a certain initial aqueous rate is done multiple priorities and consolidated, and this is multiple with identical initial aqueous
The soil sample of rate is used as one group.Wherein, the moisture content after a physico-mechanical properties for determining soil sample, such as density, consolidation；
Remaining is used for and coagulation soil sample together combine analog pile-soil interaction process, progress triaxial test.
The physical and mechanical parameter of soil sample is prepared using the soil parameters in the report of Practical Project geological mapping as reference, with reality
Engineering parameter is consistent.
3rd, soil sample physico-mechanical properties is determined, specific method is as follows：
The moisture content of soil sample is measured using dryer, the density of soil sample, quiet triaxial apparatus measurement are measured using graduated cylinder, electronic scale
The cohesive strength and internal friction angle of soil sample.
4th, soil sample and concrete sample are combined, specific method is as follows：
With reference to test model (see Fig. 2), soil sample is symmetrically cut into 4 pieces, takes 2 pieces to interlock with 2 block concrete samples and combines
Into a full standard sample.
5th, composite sample carries out the ordinary triaxial test under different confined pressures, obtains short-term shear strength；
By the composite sample of soil and concrete, disdrainage test is carried out on quiet triaxial apparatus.First apply confined pressure σ3And keep
It is constant, then apply axial stress σ1Gradually increase, until experiment failure by shear, record shear stress τ-shear strain gamma curve.
Assuming that test specimen a height of h, a diameter of d, σ1For axial stress, σ3For confined pressure, γ is soil sample shear strain, such as Fig. 4 institutes
Show.Then the shear stress on vertical contact surface isDirect stress is σ=σ3。
The axial maximum stress under multiple confined pressures is determined, shear stress τ and direct stress σ curves is drawn, determines that stake soil connects
The cohesion c and angle of friction φ of contacting surface.
6th, composite sample carries out creep triaxial test during long under different confined pressures, monitors long-term shear strain, specific method
It is as follows：
By the composite sample of soil and concrete, on quiet triaxial apparatus, first apply confined pressure σ3And keep constant, then apply
Axial stress σ1And keep constant, now shear stress isShear creep change occurs under dead load for composite sample
Shape, records shear stress τ-shear strain γ-time t curves；In same confined pressure σ3Under, change axial stress σ1Size, is carried out many
Secondary similar experiment.Obtain a plurality of shear strain γ-time t curve under different shear stress τ.
According to said procedure, and then change confined pressure size, then carry out the shear creep test under multiple axially different stress,
Obtain different confined pressure down cut stress τ-shear strain γ-time t curves.
Stress-strain diagram method analyzes the long-term shear strength of pile-soil interface, specific method under different confined pressures when the 7th, passing through etc.
It is as follows：
, should during drafting etc. according to obtained a plurality of shear stress τ-shear strain γ-time t curve under a certain confined pressure
Stress-strain curve (see Fig. 3), a plurality of curve has the asymptote of a level, and corresponding shear stress is combination examination under the confined pressure
The long-term shear strength τ of sample pile-soil interface∞。
Draw long-term shear strength τ∞With direct stress σ curves, the long-term cohesion c of pile-soil interface is determined∞With it is long-term
Internalfrictionangleφ∞。
Claims (8)
1. a kind of brief test method for determining the long-term shear strength of pile-soil interface, it is characterised in that comprise the following steps that：
(1), prepared by concrete sample
(2) soil sample, soil sample consolidation, are made
(3) soil sample physico-mechanical properties, is determined
(4), soil sample and concrete sample are combined
(5), composite sample carries out the ordinary triaxial test under different confined pressures, obtains short-term shear strength
(6), composite sample carries out creep triaxial test during long under different confined pressures, monitors long-term shear strain
(7) stress-strain diagram method analyzes the long-term shear strength of pile-soil interface under different confined pressures when, passing through etc..
2. the brief test method according to claim 1 for determining the long-term shear strength of pile-soil interface, it is characterised in that
Prepared by concrete sample, method is as follows：
Using mould, a diameter of 60mm is prepared, is highly two pieces of 50mm semicylinders concrete sample, the parameter such as intensity of sample
With reference to the parameter of pile body in Practical Project.
3. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-2, its feature exists
In making soil sample, soil sample consolidation, method is as follows：
Initial soil sample is consolidated using quiet triaxial apparatus, discharging consolidation is used when being consolidated, applies certain confined pressure, consolidation
Time is 7 days.The soil sample of a certain initial aqueous rate is done multiple priorities and consolidated, and this is multiple with identical initial aqueous rate
Soil sample is used as one group.Wherein, the moisture content after a physico-mechanical properties for determining soil sample, such as density, consolidation；Remaining
Be used for and coagulation soil sample combine analog pile-soil interaction process together, carry out triaxial test.
The physical and mechanical parameter of soil sample is prepared using the soil parameters in the report of Practical Project geological mapping as reference, with Practical Project
Parameter is consistent.
4. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-3, its feature exists
In measure soil sample physico-mechanical properties, method is as follows：
The moisture content of soil sample is measured using dryer, the density of soil sample is measured using graduated cylinder, electronic scale, quiet triaxial apparatus measures soil sample
Cohesive strength and internal friction angle.
5. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-4, its feature exists
In by soil sample and concrete sample combination, method is as follows：
Soil sample is symmetrically cut into 4 pieces, takes 2 pieces to interlock with 2 block concrete samples and is combined into a full standard sample.
6. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-5, its feature exists
In composite sample carries out the ordinary triaxial test under different confined pressures, obtains short-term shear strength, method is as follows：
By the composite sample of soil and concrete, disdrainage test is carried out on quiet triaxial apparatus.First apply confined pressure σ3And keep constant,
Apply axial stress σ again1Gradually increase, until experiment failure by shear, record shear stress τ-shear strain gamma curve.
Assuming that test specimen a height of h, a diameter of d, σ1For axial stress, σ3For confined pressure, γ is soil sample shear strain.On vertical contact surface
Shear stress beDirect stress is σ=σ3。
The axial maximum stress under multiple confined pressures is determined, shear stress τ and direct stress σ curves is drawn, determines pile-soil interface
Cohesion c and angle of friction φ.
7. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-6, its feature exists
Creep triaxial test when, composite sample carries out long under different confined pressures, monitors long-term shear strain, method is as follows：
By the composite sample of soil and concrete, on quiet triaxial apparatus, first apply confined pressure σ3And keep constant, then apply axial direction
Stress σ1And keep constant, now shear stress isShear creep deformation occurs under dead load for composite sample,
Record shear stress τ-shear strain γ-time t curves；In same confined pressure σ3Under, change axial stress σ1Size, is carried out multiple
Similar experiment.Obtain a plurality of shear strain γ-time t curve under different shear stress τ.
According to said procedure, and then change confined pressure size, then carry out the shear creep test under multiple axially different stress, obtain
Different confined pressure down cut stress τ-shear strain γ-time t curves.
8. the brief test method of the measure long-term shear strength of pile-soil interface according to claim 1-7, its feature exists
In stress-strain diagram method analyzes the long-term shear strength of pile-soil interface under different confined pressures during by waiting, and method is as follows：
Under a certain confined pressure, according to obtained a plurality of shear stress τ-shear strain γ-time t curve, stress should during drafting etc.
Varied curve, a plurality of curve has the asymptote of a level, and corresponding shear stress is composite sample stake soil contact under the confined pressure
The long-term shear strength τ in face∞。
Draw long-term shear strength τ∞With direct stress σ curves, the long-term cohesion c of pile-soil interface is determined∞Rubbed with interior for a long time
Wipe angle φ∞。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710286569.2A CN107059956B (en) | 2017-04-27 | 2017-04-27 | Simple test method for measuring long-term shear strength of pile-soil contact surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710286569.2A CN107059956B (en) | 2017-04-27 | 2017-04-27 | Simple test method for measuring long-term shear strength of pile-soil contact surface |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107059956A true CN107059956A (en) | 2017-08-18 |
| CN107059956B CN107059956B (en) | 2020-06-23 |
Family
ID=59605074
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710286569.2A Active CN107059956B (en) | 2017-04-27 | 2017-04-27 | Simple test method for measuring long-term shear strength of pile-soil contact surface |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107059956B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112362502A (en) * | 2020-12-10 | 2021-02-12 | 中南大学 | Safety evaluation method for tunnel anchorage |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1580003A1 (en) * | 1988-08-29 | 1990-07-23 | Всесоюзный научно-исследовательский институт горной геомеханики и маркшейдерского дела | Method of determining stressed state of rocks in massif |
| CN102628767A (en) * | 2012-03-23 | 2012-08-08 | 河海大学 | Device and method for testing mechanical properties of pile-soil contact surface |
| CN103822828A (en) * | 2014-02-17 | 2014-05-28 | 中国石油大学(华东) | Rock creep rupture measuring method after peak strength |
-
2017
- 2017-04-27 CN CN201710286569.2A patent/CN107059956B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1580003A1 (en) * | 1988-08-29 | 1990-07-23 | Всесоюзный научно-исследовательский институт горной геомеханики и маркшейдерского дела | Method of determining stressed state of rocks in massif |
| CN102628767A (en) * | 2012-03-23 | 2012-08-08 | 河海大学 | Device and method for testing mechanical properties of pile-soil contact surface |
| CN103822828A (en) * | 2014-02-17 | 2014-05-28 | 中国石油大学(华东) | Rock creep rupture measuring method after peak strength |
Non-Patent Citations (1)
| Title |
|---|
| 长江水利委员会长江科学院: "《水利水电工程岩石试验规程》", 28 February 2001, 中华人民共和国水利部 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112362502A (en) * | 2020-12-10 | 2021-02-12 | 中南大学 | Safety evaluation method for tunnel anchorage |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107059956B (en) | 2020-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Freilich et al. | Effective shear strength of fiber-reinforced clays | |
| Sonnenberg et al. | Centrifuge modelling of soil slopes containing model plant roots | |
| Colas et al. | Full-scale field trials to assess dry-stone retaining wall stability | |
| Zhang et al. | The compression and collapse behaviour of intact loess in suction-monitored triaxial apparatus | |
| CN105275024B (en) | Defective Big-Diameter Rock-Embedded Pile vertical bearing capacity detection and the method reinforced | |
| Xing et al. | Centrifuge tests of superlarge-diameter rock-socketed piles and their bearing characteristics | |
| Qin et al. | Fracture and deformation behaviors of saturated and dried single-edge notched beam sandstones under three-point bending based on DIC | |
| Khosravi et al. | Multistage triaxial testing to estimate effective stress relationships for unsaturated compacted soils | |
| CN105300811A (en) | Large-size soil circular shear testing machine | |
| Xiao-ling et al. | Model test study on horizontal bearing behavior of pile under existing vertical load | |
| CN106018123A (en) | Anchoring-type rock-soil-mass in-situ direct-shearing test device | |
| CN107059956A (en) | A kind of brief test method for determining the long-term shear strength of pile-soil interface | |
| CN108959759A (en) | The method for determining prismatical joint rockmass anisotropy ratio based on numerical simulation | |
| CN105223080B (en) | Evaluation method for jointed rock performance and bolting and grouting effects under compression-shear condition | |
| Xu et al. | Investigation of single pipe pile behavior under combined vertical and lateral loadings in standard and coral sands | |
| Ji | GDS Triaxial Test on the Reinforcement Effects of Bermudagrass Root-soil Complex | |
| Hu et al. | Pullout Behaviour of Belled Piles Under Axial and Oblique Pull in Soil-rock Composite Ground: An Experimental Study | |
| Deb et al. | Influence of combined vertical and lateral loading on lateral response of piled raft foundation | |
| Zhou et al. | The Ball-Surface Normal Contact Experiment Research and Numerical Simulation of Coarse Grained Soil | |
| Pan et al. | Behaviour of large post-liquefaction deformation in saturated sand-gravel composites | |
| Qian et al. | Research on the test method of the concrete expanded-plates pile | |
| Zhao et al. | Experimental investigation of the effect of evenly distributed pore pressure on rock damage | |
| Han et al. | Design and Performance of Concrete Pile Strengthened with Lengthened Steel-Tube Core: Model Tests and Numerical Simulations | |
| Sun et al. | Model tests on uplift capacity of double-belled pile influenced by distance between bells | |
| Kumar | Testing and constitutive modelling of the strain-softening behaviour of some rocks |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |