CN110344456A - A kind of experimental rig and its application method of stiff composite pile test of bearing capacity - Google Patents
A kind of experimental rig and its application method of stiff composite pile test of bearing capacity Download PDFInfo
- Publication number
- CN110344456A CN110344456A CN201910755053.7A CN201910755053A CN110344456A CN 110344456 A CN110344456 A CN 110344456A CN 201910755053 A CN201910755053 A CN 201910755053A CN 110344456 A CN110344456 A CN 110344456A
- Authority
- CN
- China
- Prior art keywords
- composite pile
- stiff composite
- soil
- diameter
- press machine
- 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.)
- Pending
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 93
- 238000012360 testing method Methods 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 22
- 239000002689 soil Substances 0.000 claims abstract description 83
- 238000011068 loading method Methods 0.000 claims abstract description 57
- 238000006073 displacement reaction Methods 0.000 claims abstract description 44
- 239000004568 cement Substances 0.000 claims abstract description 41
- 238000013500 data storage Methods 0.000 claims abstract description 19
- 238000005336 cracking Methods 0.000 claims abstract description 5
- 230000033001 locomotion Effects 0.000 claims description 20
- 238000004088 simulation Methods 0.000 claims description 17
- 229910000831 Steel Inorganic materials 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 16
- 239000010959 steel Substances 0.000 claims description 16
- 229910001018 Cast iron Inorganic materials 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 239000004567 concrete Substances 0.000 claims description 10
- 239000011398 Portland cement Substances 0.000 claims description 8
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- 238000010348 incorporation Methods 0.000 claims description 8
- 230000008961 swelling Effects 0.000 claims description 8
- 239000004576 sand Substances 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 4
- 238000005452 bending Methods 0.000 claims description 4
- 239000004927 clay Substances 0.000 claims description 4
- 238000009434 installation Methods 0.000 claims description 4
- 230000035515 penetration Effects 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 4
- KQTVWCSONPJJPE-UHFFFAOYSA-N etridiazole Chemical compound CCOC1=NC(C(Cl)(Cl)Cl)=NS1 KQTVWCSONPJJPE-UHFFFAOYSA-N 0.000 claims description 2
- 239000000843 powder Substances 0.000 claims description 2
- 238000002474 experimental method Methods 0.000 abstract description 4
- 238000011160 research Methods 0.000 abstract description 3
- 238000010998 test method Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 2
- 240000002853 Nelumbo nucifera Species 0.000 description 1
- 235000006508 Nelumbo nucifera Nutrition 0.000 description 1
- 235000006510 Nelumbo pentapetala Nutrition 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention discloses the experimental rigs and its application method of a kind of stiff composite pile test of bearing capacity, belong to core, press machine, displacement meter, data-storage system, data line outside experimental technique field in foundation engineering, including gasket ring, cushion block, high-strength inner core, soil cement；The displacement meter is connect by data line with data-storage system, and the press machine is connect by data line with data-storage system；Application method are as follows: choose press machine；Check the connection of data line；It is sequentially placed gasket ring, stiff composite pile, cushion block；Displacement meter is installed；Cracking pressure machine, and record data；Stiff composite pile destroys, and closes press machine.Under conditions of the present invention tests indoors, the field condition of composite pile is largely simulated, and analyzes the force way of composite pile on the basis of forefathers' research, targetedly uses loading method, the failure mode of composite pile is developed, provides data supporting for the theory of stiff composite pile.
Description
Technical field
The invention belongs to experimental technique fields in foundation engineering, and in particular to a kind of stiff composite pile test of bearing capacity
Experimental rig and its application method.
Background technique
Stiff composite pile is to be inserted core stake before cement mixing method initial set, and the one kind for forming common stress is new
Compound pile-type.Therefore, inner core and outer core, necessarily lead to a side skin friction between outer core and pile peripheral earth, and measure stake side and rub
Resistance is wiped mainly by collateral resistance characteristic value, the ultimate load power i.e. maximum static test pressure that unit pile body can bear are removed
With safety coefficient 2.0, the standard value that obtains.More traditional, the conventional side of existing more common lateral frictional force experimental test technology
Method lateral frictional force test method is divided into two kinds.
It is to load vertical lotus in stake top in the pre- embedding Reinforcement Stress-count of pile body one is field engineering pile loading test method
Load or horizontal loading measure the axial stress of pile body, stake top deformation and load load, obtain stake indirectly by calculating and analyzing
The collateral resistance of body.The most apparent defect of such method is to obtain pile body by the work difference and analysis of pile shaft force and pile top load
Collateral resistance, and the lateral frictional force of pile-soil interface cannot be directly measured, the hypothesis in calculating will lead to analysis result and reality
Lateral frictional force plays the error of rule, cannot really reflect the action rule of lateral frictional force.
The test method of another lateral frictional force is that the direct shear test of pile-soil interface, this method are carried out in laboratory
Can be relatively accurate, it accurately carries out experiment test and monitors the variation of collateral resistance, but due to testing indoor pile-soil interface
It is not inconsistent with engineering site, there are errors for experiment conclusion.
Therefore, be to the Curve guide impeller of existing test method it is very necessary, otherwise certainly will will limit stiff composite pile
Theoretical developments.Based on this, the invention proposes the experimental rigs and its application method of a kind of stiff composite pile test of bearing capacity.
Summary of the invention
For the above-mentioned technical problems in the prior art, the invention proposes a kind of stiff composite pile test of bearing capacity
Experimental rig and its application method, overcome the deficiencies in the prior art.Under conditions of testing indoors, largely simulate
The field condition of composite pile, and analyze on the basis of forefathers' research the force way of composite pile, targetedly using plus
Load mode develops the failure mode of composite pile, provides data supporting for the theory of stiff composite pile.
To achieve the goals above, the present invention adopts the following technical scheme:
A kind of experimental rig of stiff composite pile test of bearing capacity, it is characterised in that: including gasket ring, cushion block, high-strength inner core, cement
The outer core of soil, simulation soil layer, press machine, displacement meter, data-storage system, data line；The displacement meter passes through data line and data
Storage system connection, the press machine are connect by data line with data-storage system；
The press machine includes loading system, pressure machine support, and wherein pressure machine support includes bracket bottom plate and upper support frame
Frame, bracket bottom plate are circular configuration, and the material of bracket bottom plate is cast iron, Rockwell hardness 50-60HRC, and upper support frame is
High hardness alloy material, bending strength are greater than 300kN/mm2；
The diameter of the simulation soil layer should be greater than or equal to 3 times of core diameter outside soil cement, the type for simulating soil layer should select layer
The weak soil of shape or middle pan soil, the standard penetration test (SPT) for simulating soil layer hit several N values no more than 80.
Preferably, the material of the gasket ring is cast iron, and the outer diameter of Rockwell hardness 40-50HRC, gasket ring are greater than or equal to mould
The diameter of quasi- soil layer, the internal diameter of gasket ring is greater than or equal to the diameter of high-strength inner core, and the internal diameter of gasket ring is greater than the straight of high-strength inner core
The part of diameter is no more than the half of the difference of the outer core diameter of soil cement and high-strength inner core diameter, and the height of gasket ring is 5-10cm.
Preferably, the material of the cushion block is cast iron, and the diameter of Rockwell hardness 40-50HRC, cushion block are less than or equal to height
Strong inner core diameter, and the diameter of cushion block is less than 1/8th of part no more than high-strength inner core diameter of high-strength inner core diameter, pad
The height of block is 5-10cm.
Preferably, the material of the high-strength inner core is concrete, and strength grade of concrete is not less than C50.
Preferably, the composition material of the outer core of the soil cement is ordinary portland cement, the soil body, swelling agent, water, wherein
The content of ordinary portland cement accounts for the 10%-20% of entire stiff composite pile volume, and the incorporation of swelling agent is cement mixed weight
0%-10%, the incorporation of water is the 5%-20% of entire stiff composite pile volume, and the unconfined compressive strength of soil cement is greater than etc.
In 10MPa.
Preferably, the displacement is calculated as two groups, and every group two, first group is mounted on the rigid steel disc of square for being close to cushion block
On, two displacement meters are symmetrical about cushion block central point；Second group is mounted on the rigid steel of square for being close to the outer core of soil cement
On piece, two displacement meters are symmetrical about the central point of core outside soil cement, rigid steel disc with a thickness of 1-3mm, rigid steel disc
Side length be 3-5cm, the precision of the displacement meter is 0.001mm, and range is not less than 100mm.
Preferably, the type of the simulation soil layer can be the single muck soil of stratiform, artificial earth fill, powder clay, red
The combination of clay, Extra-fine sand, thick middle sand or a variety of soil bodys.
A kind of experimental rig application method of stiff composite pile test of bearing capacity, it is characterised in that: using such as claim 1
The experimental rig of a kind of stiff composite pile test of bearing capacity, after stiff composite pile preparation is completed, using such as lower section
Method is tested:
Step 1: choosing press machine, the movement speed of press machine is 0.01mm/min-100mm/min, the load system in press machine
System is driven using numerical control hydraulic, and shift motion should be not less than 10cm, and the peak load that press machine can apply is not less than 1000kN；
Step 2: checking the working condition of press machine, check the connection of data line and displacement meter；
Step 3: gasket ring being placed on press base, is overlapped gasket ring center with press base central axes；
Step 4: stiff composite pile being placed on gasket ring, is overlapped the central axes of stiff composite pile with gasket ring center；
Step 5: cushion block being placed on stiff composite pile, is overlapped cushion block center with stiff composite pile central axes；
Step 6: installation displacement meter is in 4 displacement meters in same perpendicular；
Step 7: cracking pressure machine, before loading system is contacted with stiff composite pile, the movement speed of loading system is 5-
When the distance between loading system to be added and stiff composite pile are 0.1-0.5cm, the movement speed of loading system is dropped by 20mm/min
Low is that the movement speed of loading system is reduced to 1mm/min when loading system to be added and stiff composite pile contact by 1-2mm/min；
Step 8: vertical precompressed, formal load keep vertical pressure not when the vertical stress that loading system applies is 0.2MPa
Become, start formal load, formal loading velocity is 0.02mm/min-1mm/min, records loading system by data-storage system
Pressure, i.e., the side friction between the outer core of high-strength inner core and soil cement；
Step 9: sharply declining after collateral resistance reaches peak value, when collateral resistance is down to the 50%-80% of peak value moment, or when high-strength interior
Core and the outer core of soil cement occur the opposite changing of the relative positions and stop load when changing of the relative positions distance is greater than 2cm；
Step 10: off-load being carried out to loading system, after loading system and stiff composite pile disengaging, sample is taken out and retains, and is right
Test data is arranged, and obtains collateral resistance with the curve graph of change in displacement.
Advantageous effects brought by the present invention:
(1) experimental rig of the invention can be realized the experimental test of live pile side resistance, be overcome with the vertical collateral resistance of pile body
The indirect of traditional situ loading method calculates the error for deriving lateral frictional force and laboratory configures pile-soil interface
The untrue test result of sample.(2) vertical load loading system uses high-intensitive scalable axle power bar load, passes through axle power
The method that loading unit controls axle power size respectively can achieve and apply micro- vertical axle power incremental step, and fine adjustment in real time is vertical
The purpose of load, meanwhile, Vertical Settlement, the degree that the vertical collateral resistance of reflection stake plays can be monitored in real time in multiple displacement meters.(3)
Effect of the invention is that the apparatus structure is simple, easy to use, is easily portable, reusable, does not have to practical test pile, cost
Few, expense is low, and efficiency-cost ratio is high, can actual loading deformation condition of the ground foundation simulation soil under foundation pile effect, can be in Pile integrity
Stake resistance relevant parameter is provided before construction, and assists providing the parameters such as modulus of shearing, the compression modulus of foundation soil.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of stiff composite pile collateral resistance test equipment of the present invention and its test method.
Fig. 2 is the structural schematic diagram of press machine in stiff composite pile collateral resistance test equipment of the present invention and its test method.
Wherein, 1- gasket ring；2- cushion block；The high-strength inner core of 3-；The outer core of 4- soil cement；5- simulates soil layer；6- press machine；7- displacement
Meter；8- data-storage system；9- data line；10- loading system；11- pressure machine support.
Specific embodiment
With reference to the accompanying drawing and specific embodiment invention is further described in detail:
Embodiment 1:
It is tested with a kind of stiff composite pile collateral resistance test equipment of the present invention and its test method, Model Pile each section
Size are as follows: concrete inner core diameter is 200mm, is highly 500mm, and it is highly 500mm that the outer core diameter of soil cement, which is 500mm,.
Such as Fig. 1-2, a kind of experimental rig of stiff composite pile test of bearing capacity, it is characterised in that: including gasket ring 1, cushion block
2, the outer core 4 of high-strength inner core 3, soil cement, simulation soil layer 5, press machine 6, displacement meter 7, data-storage system 8, data line 9；It is described
Displacement meter is connect by data line 9 with data-storage system 8, and the press machine 6 is connected by data line 9 and data-storage system 8
It connects；
The press machine 6 includes loading system 10, pressure machine support 11, and wherein pressure machine support 11 includes bracket bottom plate and top
Braced frame, bracket bottom plate are circular configuration, and the material of bracket bottom plate is cast iron, Rockwell hardness 50HRC, upper support frame
For high hardness alloy material, bending strength 300kN/mm2；
The diameter of the simulation soil layer 5 is equal to 3 times of soil cement 4 diameter of outer core, and the type of simulation soil layer 5 selects the soft of stratiform
Soil, it is 40 that several N values are hit in the standard penetration test (SPT) of simulation soil layer 5.
Preferably, the material of the gasket ring 1 is cast iron, and the outer diameter of Rockwell hardness 40HRC, gasket ring 1 are greater than or equal to mould
The diameter of quasi- soil layer 5, the internal diameter of gasket ring 1 is greater than or equal to the diameter of high-strength inner core 3, and the internal diameter of gasket ring 1 is greater than high-strength inner core 3
Diameter part be no more than outer 3 diameter of 4 diameter of core and high-strength inner core of soil cement difference half, the height of gasket ring 1 is 5cm.
Preferably, the material of the cushion block 2 is cast iron, and the diameter of Rockwell hardness 40HRC, cushion block 2 are equal to high-strength inner core 3
Diameter, the height of cushion block 2 are 5cm.
Preferably, the material of the high-strength inner core 3 is concrete, and strength grade of concrete is not less than C50.
Preferably, the composition material of the outer core 4 of the soil cement is ordinary portland cement, the soil body, swelling agent, water, wherein
The content of ordinary portland cement accounts for the 12% of entire stiff composite pile volume, and the incorporation of swelling agent is cement mixed weight
0.5%, the incorporation of water is the 10% of entire stiff composite pile volume, and the unconfined compressive strength of soil cement is equal to 10MPa.
Preferably, the displacement meter 7 is two groups, and every group two, first group is mounted on the rigid steel of square for being close to cushion block 2
On piece, two displacement meters 7 are symmetrical about 2 central point of cushion block；Second group has been mounted on the square of the outer core 4 of abutting soil cement just
Property steel disc on, two displacement meters 7 are symmetrical about the central point of core 4 outside soil cement, rigid steel disc with a thickness of 1mm, rigidity
The side length of steel disc is 3cm, and the precision of the displacement meter 7 is 0.001mm, and range is not less than 100mm.
Preferably, the type of the simulation soil layer 5 is the single muck soil of stratiform.
A kind of experimental rig application method of stiff composite pile test of bearing capacity, it is characterised in that: using such as claim 1
The experimental rig of a kind of stiff composite pile test of bearing capacity, after stiff composite pile preparation is completed, using such as lower section
Method is tested:
Step 1: choosing press machine 6, the movement speed of press machine 6 is 0.01mm/min-100mm/min, the load in press machine 6
System 10 is driven using numerical control hydraulic, and shift motion should be not less than 10cm, and the peak load that press machine 6 can apply is not less than
1000kN；
Step 2: checking the working condition of press machine 6, check the connection of data line 9 and displacement meter 7；
Step 3: gasket ring 1 being placed on 6 pedestal of press machine, is overlapped 1 center of gasket ring with 6 base center axis line of press machine；
Step 4: stiff composite pile being placed on gasket ring 1, is overlapped the central axes of stiff composite pile with 1 center of gasket ring；
Step 5: cushion block 2 being placed on stiff composite pile, is overlapped 2 center of cushion block with stiff composite pile central axes；
Step 6: installation displacement meter 7 is in 4 displacement meters 7 in same perpendicular；
Step 7: cracking pressure machine 6, before loading system 10 is contacted with stiff composite pile, the movement speed of loading system 10 is
When the distance between loading system 10 and stiff composite pile to be added are 0.3cm, the movement speed of loading system 10 is dropped by 10mm/min
Low is 2mm/min, and when loading system 10 to be added is contacted with stiff composite pile, the movement speed of loading system 10 is reduced to 1mm/
min；
Step 8: vertical precompressed, formal load keep vertical pressure when the vertical stress that loading system 10 applies is 0.2MPa
It is constant, start formal load, formal loading velocity is 0.02mm/min, and the pressure of loading system is recorded by data-storage system 8
Side friction between the outer core 4 of power, i.e., high-strength inner core 3 and soil cement；
Step 9: sharply decline after collateral resistance reaches peak value, when collateral resistance is down to the 0% of peak value moment, or when high-strength inner core 3 with
The outer core 4 of soil cement occurs the opposite changing of the relative positions and stops load when changing of the relative positions distance is greater than 2cm；
Step 10: off-load is carried out to loading system 10, after loading system 10 and stiff composite pile disengaging, sample is taken out and retains,
And test data is arranged, collateral resistance is obtained with the curve graph of change in displacement.
Embodiment 2:
It is tested with a kind of stiff composite pile collateral resistance test equipment of the present invention and its test method, Model Pile each section
Size are as follows: concrete inner core diameter is 250mm, is highly 500mm, and it is highly 500mm that the outer core diameter of soil cement, which is 500mm,.
Such as Fig. 1-2, a kind of experimental rig of stiff composite pile test of bearing capacity, it is characterised in that: including gasket ring 1, cushion block
2, the outer core 4 of high-strength inner core 3, soil cement, simulation soil layer 5, press machine 6, displacement meter 7, data-storage system 8, data line 9；It is described
Displacement meter is connect by data line 9 with data-storage system 8, and the press machine 6 is connected by data line 9 and data-storage system 8
It connects；
The press machine 6 includes loading system 10, pressure machine support 11, and wherein pressure machine support 11 includes bracket bottom plate and top
Braced frame, bracket bottom plate are circular configuration, and the material of bracket bottom plate is cast iron, Rockwell hardness 50HRC, upper support frame
For high hardness alloy material, bending strength 350kN/mm2；
The diameter of the simulation soil layer 5 is equal to 4 times of soil cement 4 diameter of outer core, and the type of simulation soil layer 5 selects hard in stratiform
Soil, it is 60 that several N values are hit in the standard penetration test (SPT) of simulation soil layer 5.
Preferably, the material of the gasket ring 1 is cast iron, and Rockwell hardness 50HRC, the outer diameter of gasket ring 1, which is equal to, simulates soil layer 5
Diameter, the internal diameter of gasket ring 1 is equal to the diameter of high-strength inner core 3, and the height of gasket ring 1 is 7cm.
Preferably, the material of the cushion block 2 is cast iron, and the diameter of Rockwell hardness 50HRC, cushion block 2 are less than high-strength inner core 3
Diameter, and it is 1st/16th of high-strength 3 diameter of inner core that the diameter of cushion block 2, which is less than the part of high-strength 3 diameter of inner core, cushion block 2
Height is 5cm.
Preferably, the material of the high-strength inner core 3 is concrete, and strength grade of concrete is C60.
Preferably, the composition material of the outer core 4 of the soil cement is ordinary portland cement, the soil body, swelling agent, water, wherein
The content of ordinary portland cement accounts for the 15% of entire stiff composite pile volume, and the incorporation of swelling agent is the 1% of cement mixed weight,
The incorporation of water is the 12% of entire stiff composite pile volume, and the unconfined compressive strength of soil cement is equal to 10MPa.
Preferably, the displacement meter 7 is two groups, and every group two, first group is mounted on the rigid steel of square for being close to cushion block 2
On piece, two displacement meters 7 are symmetrical about 2 central point of cushion block；Second group has been mounted on the square of the outer core 4 of abutting soil cement just
Property steel disc on, two displacement meters 7 are symmetrical about the central point of core 4 outside soil cement, rigid steel disc with a thickness of 1mm, rigidity
The side length of steel disc is 3cm, and the precision of the displacement meter 7 is 0.001mm, and range is not less than 100mm.
Preferably, the type of the simulation soil layer 5 is the thick middle sand of stratiform.
A kind of experimental rig application method of stiff composite pile test of bearing capacity, it is characterised in that: using such as claim 1
The experimental rig of a kind of stiff composite pile test of bearing capacity, after stiff composite pile preparation is completed, using such as lower section
Method is tested:
Step 1: choosing press machine 6, the movement speed of press machine 6 is 0.01mm/min-100mm/min, the load in press machine 6
System 10 is driven using numerical control hydraulic, and shift motion should be not less than 10cm, and the peak load that press machine 6 can apply is not less than
1000kN；
Step 2: checking the working condition of press machine 6, check the connection of data line 9 and displacement meter 7；
Step 3: gasket ring 1 being placed on 6 pedestal of press machine, is overlapped 1 center of gasket ring with 6 base center axis line of press machine；
Step 4: stiff composite pile being placed on gasket ring 1, is overlapped the central axes of stiff composite pile with 1 center of gasket ring；
Step 5: cushion block 2 being placed on stiff composite pile, is overlapped 2 center of cushion block with stiff composite pile central axes；
Step 6: installation displacement meter 7 is in 4 displacement meters 7 in same perpendicular；
Step 7: cracking pressure machine 6, before loading system 10 is contacted with stiff composite pile, the movement speed of loading system 10 is
When the distance between loading system 10 and stiff composite pile to be added are 0.5cm, the movement speed of loading system 10 is dropped by 20mm/min
Low is 2mm/min, and when loading system 10 to be added is contacted with stiff composite pile, the movement speed of loading system 10 is reduced to 1mm/
min；
Step 8: vertical precompressed, formal load keep vertical pressure when the vertical stress that loading system 10 applies is 0.2MPa
It is constant, start formal load, formal loading velocity is 0.05/min, the pressure of loading system is recorded by data-storage system 8,
Side friction between i.e. high-strength inner core 3 and the outer core 4 of soil cement；
Step 9: sharply declining after collateral resistance reaches peak value, when collateral resistance is down to the 80% of peak value moment, or work as high-strength inner core 3
The opposite changing of the relative positions occurs when changing of the relative positions distance is greater than 2cm with core 4 outside soil cement and stops load；
Step 10: off-load is carried out to loading system 10, after loading system 10 and stiff composite pile disengaging, sample is taken out and retains,
And test data is arranged, collateral resistance is obtained with the curve graph of change in displacement.
The present invention a kind of experimental rig and its application method of stiff composite pile test of bearing capacity, the condition tested indoors
Under, the field condition of composite pile is largely simulated, and the stress side of composite pile is analyzed on the basis of forefathers' research
Formula targetedly uses loading method, develops the failure mode of composite pile, provide data branch for the theory of stiff composite pile
Support.
Certainly, the above description is not a limitation of the present invention, and the present invention is also not limited to the example above, this technology neck
The variations, modifications, additions or substitutions that the technical staff in domain is made within the essential scope of the present invention also belong to guarantor of the invention
Protect range.
Claims (8)
1. a kind of experimental rig of stiff composite pile test of bearing capacity, it is characterised in that: including gasket ring, cushion block, high-strength inner core, water
The outer core of soil, simulation soil layer, press machine, displacement meter, data-storage system, data line；The displacement meter passes through data line and number
It is connected according to storage system, the press machine is connect by data line with data-storage system；
The press machine includes loading system, pressure machine support, and wherein pressure machine support includes bracket bottom plate and upper support frame
Frame, bracket bottom plate are circular configuration, and the material of bracket bottom plate is cast iron, Rockwell hardness 50-60HRC, and upper support frame is
High hardness alloy material, bending strength are greater than 300kN/mm2；
The diameter of the simulation soil layer should be greater than or equal to 3 times of core diameter outside soil cement, the type for simulating soil layer should select layer
The weak soil of shape or middle pan soil, the standard penetration test (SPT) for simulating soil layer hit several N values no more than 80.
2. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that the pad
The material of ring is cast iron, Rockwell hardness 40-50HRC, and the outer diameter of gasket ring is greater than or equal to the diameter of simulation soil layer, gasket ring it is interior
Diameter is greater than or equal to the diameter of high-strength inner core, and the internal diameter of gasket ring is greater than the part of the diameter of high-strength inner core no more than outside soil cement
The half of the difference of core diameter and high-strength inner core diameter, the height of gasket ring are 5-10cm.
3. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that the pad
The material of block is cast iron, and the diameter of Rockwell hardness 40-50HRC, cushion block are less than or equal to high-strength inner core diameter, and cushion block is straight
The part that diameter is less than high-strength inner core diameter is no more than 1/8th of high-strength inner core diameter, and the height of cushion block is 5-10cm.
4. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that the height
The material of strong inner core is concrete, and strength grade of concrete is not less than C50.
5. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that the water
The composition material of the outer core of soil is ordinary portland cement, the soil body, swelling agent, water, wherein the content of ordinary portland cement accounts for
The 10%-20% of entire stiff composite pile volume, the incorporation of swelling agent are the 0%-10% of cement mixed weight, and the incorporation of water is whole
The unconfined compressive strength of the 5%-20% of a stiff composite pile volume, soil cement are more than or equal to 10MPa.
6. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that institute's rheme
Shifting is calculated as two groups, and every group two, first group is mounted on the rigid steel disc of square for being close to cushion block, and two displacement meters are about cushion block
Central point is symmetrical；Second group is mounted on the rigid steel disc of square for being close to the outer core of soil cement, and two displacement meters are about water
The central point of the outer core of soil is symmetrical, rigid steel disc with a thickness of 1-3mm, the side length of rigid steel disc is 3-5cm, the displacement
The precision of meter is 0.001mm, and range is not less than 100mm.
7. a kind of experimental rig of stiff composite pile test of bearing capacity according to claim 1, which is characterized in that the mould
The type of quasi- soil layer can be the single muck soil of stratiform, artificial earth fill, powder clay, red clay, Extra-fine sand, it is thick in sand or
The combination of a variety of soil bodys.
8. a kind of experimental rig application method of stiff composite pile test of bearing capacity, it is characterised in that: using such as claim 1 institute
A kind of experimental rig for the stiff composite pile test of bearing capacity stated, after stiff composite pile preparation is completed, with the following method
It is tested:
Step 1: choosing press machine, the movement speed of press machine is 0.01mm/min-100mm/min, the load system in press machine
System is driven using numerical control hydraulic, and shift motion should be not less than 10cm, and the peak load that press machine can apply is not less than 1000kN；
Step 2: checking the working condition of press machine, check the connection of data line and displacement meter；
Step 3: gasket ring being placed on press base, is overlapped gasket ring center with press base central axes；
Step 4: stiff composite pile being placed on gasket ring, is overlapped the central axes of stiff composite pile with gasket ring center；
Step 5: cushion block being placed on stiff composite pile, is overlapped cushion block center with stiff composite pile central axes；
Step 6: installation displacement meter is in 4 displacement meters in same perpendicular；
Step 7: cracking pressure machine, before loading system is contacted with stiff composite pile, the movement speed of loading system is 5-
When the distance between loading system to be added and stiff composite pile are 0.1-0.5cm, the movement speed of loading system is dropped by 20mm/min
Low is that the movement speed of loading system is reduced to 1mm/min when loading system to be added and stiff composite pile contact by 1-2mm/min；
Step 8: vertical precompressed, formal load keep vertical pressure not when the vertical stress that loading system applies is 0.2MPa
Become, start formal load, formal loading velocity is 0.02mm/min-1mm/min, records loading system by data-storage system
Pressure, i.e., the side friction between the outer core of high-strength inner core and soil cement；
Step 9: sharply declining after collateral resistance reaches peak value, when collateral resistance is down to the 50%-80% of peak value moment, or when high-strength interior
Core and the outer core of soil cement occur the opposite changing of the relative positions and stop load when changing of the relative positions distance is greater than 2cm；
Step 10: off-load being carried out to loading system, after loading system and stiff composite pile disengaging, sample is taken out and retains, and is right
Test data is arranged, and obtains collateral resistance with the curve graph of change in displacement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910755053.7A CN110344456A (en) | 2019-08-15 | 2019-08-15 | A kind of experimental rig and its application method of stiff composite pile test of bearing capacity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910755053.7A CN110344456A (en) | 2019-08-15 | 2019-08-15 | A kind of experimental rig and its application method of stiff composite pile test of bearing capacity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110344456A true CN110344456A (en) | 2019-10-18 |
Family
ID=68185172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910755053.7A Pending CN110344456A (en) | 2019-08-15 | 2019-08-15 | A kind of experimental rig and its application method of stiff composite pile test of bearing capacity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110344456A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111289351A (en) * | 2020-03-23 | 2020-06-16 | 中铁二院工程集团有限责任公司 | Composite light pile group pile bearing capacity detection device, system and method |
| CN111456117A (en) * | 2020-04-02 | 2020-07-28 | 中北大学 | Pile forming loading model test device and method for stiff composite pile |
| CN111622273A (en) * | 2020-05-08 | 2020-09-04 | 浙江大学 | Test device and test method for simulating pile foundation bearing performance of precast pile filled with discrete drainage materials around |
| CN113863401A (en) * | 2021-12-06 | 2021-12-31 | 中建安装集团有限公司 | Stress detection device for complex load launching soil composite pile |
| CN115094961A (en) * | 2022-07-13 | 2022-09-23 | 南京工业大学 | Long-term monitoring device and method for bearing performance of stiff composite pile |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102628767A (en) * | 2012-03-23 | 2012-08-08 | 河海大学 | Device and method for testing mechanical properties of pile-soil contact surface |
| CN210507566U (en) * | 2019-08-15 | 2020-05-12 | 北京中岩大地科技股份有限公司 | Test device for bearing capacity test of stiff composite pile |
-
2019
- 2019-08-15 CN CN201910755053.7A patent/CN110344456A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102628767A (en) * | 2012-03-23 | 2012-08-08 | 河海大学 | Device and method for testing mechanical properties of pile-soil contact surface |
| CN210507566U (en) * | 2019-08-15 | 2020-05-12 | 北京中岩大地科技股份有限公司 | Test device for bearing capacity test of stiff composite pile |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111289351A (en) * | 2020-03-23 | 2020-06-16 | 中铁二院工程集团有限责任公司 | Composite light pile group pile bearing capacity detection device, system and method |
| CN111456117A (en) * | 2020-04-02 | 2020-07-28 | 中北大学 | Pile forming loading model test device and method for stiff composite pile |
| CN111622273A (en) * | 2020-05-08 | 2020-09-04 | 浙江大学 | Test device and test method for simulating pile foundation bearing performance of precast pile filled with discrete drainage materials around |
| CN111622273B (en) * | 2020-05-08 | 2021-04-23 | 浙江大学 | Test device and test method for simulating pile foundation bearing performance of precast pile filled with discrete drainage materials around |
| CN113863401A (en) * | 2021-12-06 | 2021-12-31 | 中建安装集团有限公司 | Stress detection device for complex load launching soil composite pile |
| CN115094961A (en) * | 2022-07-13 | 2022-09-23 | 南京工业大学 | Long-term monitoring device and method for bearing performance of stiff composite pile |
| CN115094961B (en) * | 2022-07-13 | 2023-05-26 | 南京工业大学 | Long-term monitoring device and method for bearing performance of stiff composite pile |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110344456A (en) | A kind of experimental rig and its application method of stiff composite pile test of bearing capacity | |
| CN109839315B (en) | Bidirectional sliding type physical model box and cross-fault tunnel mechanical behavior testing method | |
| CN104165807B (en) | Large-deflection destruction testing device and method for prestressed concrete plate beam | |
| CN108613885B (en) | Indoor test method for simulating pile side post grouting | |
| CN108828195B (en) | Indoor test method for simulating upward return of post-grouting slurry at pile end | |
| CN105223080B (en) | Evaluation method for jointed rock performance and bolting and grouting effects under compression-shear condition | |
| Katzenbach et al. | Design of axially loaded piles and pile groups—German practice | |
| Wang et al. | Investigation of the mechanical properties of double lining structure of shield tunnel with different joint surface | |
| CN106153462A (en) | A kind of asphalt pressure turns round failure by shear performance test apparatus | |
| CN107219131B (en) | A kind of asphalt horizontal shear performance test apparatus and method considering local axial compressive force | |
| KR200269540Y1 (en) | Large Cyclic Triaxial Testing Apparatus | |
| CN210507566U (en) | Test device for bearing capacity test of stiff composite pile | |
| Brown | The rapid load testing of piles in fine grained soils. | |
| CN108398319B (en) | Ultra-high water filling material creep test device and use method thereof | |
| CN218212441U (en) | Side limit annular direct shear apparatus for simulating shear strength of pile-mudstone contact surface | |
| Sakr et al. | Lateral behaviour of composite tapered piles in dense sand | |
| CN113686603B (en) | Combined bearing simulation test method for surrounding rock and lining structure of deep-buried tunnel | |
| Nilsson | Evaluation of in-situ measurements of composite bridge with integral abutments | |
| CN110387914A (en) | A kind of test method of stiff composite pile bearing capacity circumferential direction test | |
| Barla et al. | Setting up a new direct shear testing apparatus | |
| Joo | Behaviour of large scale rigid model piles under inclined loads in sand | |
| Vlahos et al. | Development of a model jack-up unit for the study of soil-structure interaction on clay | |
| Lekarp et al. | Development of a large-scale triaxial apparatus for characterization of granular materials | |
| Fæste | Buried flexible structures: modeling and field behavior | |
| Kim et al. | Load rating and FRP retrofitting of bridge abutment timber piles. |
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 |