Test apparatus for pile-soil interface shear mechanical properties

Patent metadata

Field	Value
Publication number	US-10907320-B2
Application number	US-201916533831-A
Country	US
Kind code	B2
Filing date	Aug 7, 2019
Priority date	Jun 8, 2018
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Embodiments of the present disclosure provide a test apparatus for pile-soil interface shear mechanical properties, comprising a support device, a pressure device, a membrane box, and a thrust device; wherein the support device comprises a bottom plate, a top plate, a support beam, and a plurality of bracing struts, the bottom plate and the top plate being both provided with a through-hole for inserting a model pile. The test apparatus for pile-soil interface shear mechanical properties according to the present disclosure has a simple structure and is easy to operate, which may accurately simulate mechanical properties of pile soils having different types of piled foundations in actual works, thereby facilitating researches on pile-soil testing.

First claim

We claim:

1. A test apparatus for pile-soil interface shear mechanical properties, comprising: a support device ( 1 ), a pressure device ( 2 ), a membrane box ( 3 ), and a thrust device ( 4 ); wherein the support device comprises a bottom plate ( 1 . 1 ), a top plate ( 1 . 2 ), and a support beam ( 1 . 3 ), the bottom plate and the top plate being connected via a plurality of bracing struts ( 1 . 4 ), the support beam being disposed above the top plate; the pressure device is disposed on the support beam and arranged for applying a vertical pressure against a model pile ( 5 ); a membrane barrel ( 3 . 1 ) of the membrane box is vertically disposed on the bottom plate and sleeved at a radial outer side of the model pile, an accommodating cavity being provided between the membrane barrel and the model pile; the thrust device is sleeved on the membrane barrel and arranged for applying a plurality of horizontal thrusting forces against the membrane barrel so as to squeeze a model soil ( 6 ) in the membrane barrel along a direction perpendicular to an axial direction of the model pile, the plurality of horizontal thrusting forces incrementing linearly from top to down.

2. The test apparatus for pile-soil, interface shear mechanical properties according to claim 1 , characterized in that the thrust device comprises a thrust cylinder group, a plurality of thrust assemblies evenly arranged along a circumferential direction of a center of the thrust cylinder group, and a protective barrel ( 4 . 5 ) sleeved on an outer circumferential wall of the thrust cylinder group;
the thrust cylinder group includes a plurality of radially contractile thrust cylinders ( 4 . 1 ), the plurality of thrust cylinders being axially stacked on the bottom plate, adjacent two of the thrust cylinders being not fixedly connected;
each of the thrust assemblies includes a vertically arranged push plate ( 4 . 2 ), a plurality of horizontally-arranged contractile thrust arms ( 4 . 3 ), and a plurality of thrust springs ( 4 . 4 ), wherein the plurality of thrust arms are arranged in, a same vertical plane along a top-down direction, outer ends of the plurality of thrust arms are all connected to the push plate, inner ends of the plurality of thrust arms are connected to the thrust cylinders, respectively, and the thrust arms are disposed in one-to-one correspondence to the thrust cylinders; each thrust arm is sleeved with one thrust spring; and
a plurality of side holes ( 4 . 5 a ) are provided in a side wall of the protective barrel, for the thrust arms and the thrust springs to penetrate through.

3. The test apparatus for pile-soil interface shear mechanical properties according to claim 2 , characterized in that the thrust cylinder is a double-layered cylindrical body structure, an inner-layer cylindrical body and an outer-layer cylindrical body being co-axially sleeved, the inner-layer cylindrical body being enclosed by a plurality of arcuate steel sheets ( 4 . 1 a ) evenly arranged at intervals along a circumferential direction of the inner-layer cylindrical body, the outer-layer cylindrical body being enclosed by a plurality of arcuate steel plates ( 4 . 1 b ) evenly arranged at intervals along a circumferential direction of the outer-layer cylindrical body; a spacing clearance between adjacent two arcuate steel sheets and a spacing clearance between adjacent two arcuate steel plates are staggered internally and externally, each arcuate steel plate being horizontally slidably-fitted with two arcuate steel sheets disposed internal thereto along a circumferential direction of the thrust cylinder; inner ends of the plurality of thrust arms are connected to the arcuate steel plates, respectively; and the thrust arms and the arcuate steel plates are disposed in one-to-one correspondence; and
the thrust arms at a same layer connected to the same thrust cylinder are disposed at a same horizontal plane, and the inner ends of the thrust arms at the same layer are all pointed to a central axial line of the thrust cylinder.

4. The test apparatus for pile-soil interface shear mechanical properties according to claim 3 , characterized in that the thrust arm comprises a solid rod ( 4 . 3 a ) and a hollow rod ( 4 . 3 b ), an inner end of the solid rod being connected to an outer sidewall of the arcuate steel plate, an outer end of the solid rod being slidably inserted into the hollow rod.

5. The test apparatus for pile-soil, interface shear mechanical properties according to claim 4 , characterized in that free lengths of the thrust springs sleeved on the thrust arms at the same layer are equal, and elastic coefficients of the thrust springs sleeved on each layer of thrust arms increment linearly from top to down.

6. The test apparatus for pile-soil interface shear mechanical properties according to claim 4 , characterized in that a nut ( 4 . 3 ) is provided on the hollow rod; the thrust springs are disposed between the nut and the arcuate steel plate; and the free lengths and elastic coefficients of all thrust springs are equal.

7. The test apparatus for pile-soil interface shear mechanical properties according to claim 2 , characterized in that the top plate and the bottom plate are both circulate plates, the bottom plate and the top plate are both provided with a plurality of positioning devices evenly arranged along a circumferential direction of respective center thereof, and each of the positioning devices includes an elongated slotted eye ( 1 a ) arranged along a radial direction of the bottom plate, a plurality of clamping posts ( 1 b ) disposed at two sides of a length direction of the elongated slotted eye, and a latch bolt ( 1 c ) for positioning internal and external positions of the push plate on the support device.

8. The test apparatus for pile-soil interface shear mechanical properties according to claim 1 , characterized in that a through-hole A and a through-hole B for inserting the model pile are provided on the bottom plate and the top plate, respectively; the plurality of bracing struts are all arranged through the bottom plate and the top plate from top to down; the support beam is connected to the plurality of bracing struts, a through-hole C being provided on the support beam;
the pressure device comprises vertical loading means ( 2 . 1 ), a dowel rod ( 2 . 2 ), a pressure sensor ( 2 . 3 ), and a displacement sensor ( 2 . 4 ); the vertical loading means is detachably disposed on the support beam; the dowel rod is arranged through the through-hole C, one end of which is connected to the vertical loading means, the other end of which is in contact with a top end of the model pile; the pressure sensor and the displacement sensor are sandwiched between the dowel rod and the model pile;
the membrane box comprises a membrane barrel ( 3 . 1 ), a permeable plate ( 3 . 2 ), and a blank cover ( 3 . 3 ); wherein the membrane barrel is made of a flexible material; the permeable plate is disposed inside the membrane barrel to block a lower port of the membrane barrel; the blank cover is disposed at a top portion of the membrane barrel to seal an upper port of the membrane barrel; the permeable plate and the blank cover are provided with a through-hole D and a through-hole E, respectively, an upper end and a lower end of the model pile being arranged through the through-hole E and the through-hole D, respectively.

9. The test apparatus for pile-soil interface shear mechanical properties according to claim 8 , characterized in that the permeable plate comprises a permeable plate body and a flexible membrane disposed peripheral to the permeable plate body, the through-hole D being disposed on the permeable plate body; the membrane box further comprises at least three holding-down

Assignees

• Univ Central South
• Univ Henan Polytechnic

Inventors

• Tan Junkun
• Guo Jiaqi
• Huang Shanxiu
• Qiao shifan

Classifications

• E02D33/00 Primary

  Testing foundations or foundation structures (testing methods and apparatus, see the relevant subclasses of class G01; testing structures or apparatus as regards function, in general, G01M; testing or determining chemical or physical properties, in general G01N) · CPC title

• G01N3/062

  with mechanical indicating or recording means · CPC title

• G01N3/24

  by applying steady shearing forces (G01N3/26, G01N3/28 take precedence) · CPC title

• G01N2203/0284

  Bulk material, e.g. powders · CPC title

• G01N2203/0025

  Shearing · CPC title