CN106053127B

CN106053127B - Method for performing undisturbed soil model test on half-pile by using detachable soil sampler

Info

Publication number: CN106053127B
Application number: CN201610363132.XA
Authority: CN
Inventors: 钱永梅; 王若竹; 田伟; 金玉杰; 谢新颖
Original assignee: Jilin Jianzhu University
Current assignee: Jilin Jianzhu University
Priority date: 2016-05-30
Filing date: 2016-05-30
Publication date: 2021-04-13
Anticipated expiration: 2036-05-30
Also published as: CN106053127A

Abstract

A method for carrying out an undisturbed soil model test of a half-pile by utilizing a detachable soil sampler belongs to the technical field of buildings, and is characterized in that the soil sampler is used for sampling soil on a test site, the soil sampler consists of two plane plates and two side plates to form a bottomless and uncovered box body, one plane plate is detached, a groove of the half-pile model is dug out on the surface of a soil sample, the half-pile model is placed in a small groove to produce a pile soil test piece, a glass plate is placed on the surface of the pile soil pressed with the half-pile model and is fixed with the soil sampler, and therefore, the pile soil test piece of the half-pile undisturbed soil model test is prepared and can be placed on a test bed for carrying out a loading test. The invention can conveniently bury the pile model while finishing the target of taking undisturbed soil on site, and adopts the mode of digging groove, the pile is accurately positioned, the visible glass surface is fixed by clamping, the operation is very simple and convenient, so as to ensure that the manufactured test piece has good effect and the test result has strong reliability.

Description

Method for performing undisturbed soil model test on half-pile by using detachable soil sampler

Technical Field

The invention belongs to the technical field of buildings, and relates to a method for testing an undisturbed soil model of a pile body.

Background

The concrete expanding disk pile is a main form of the present variable cross-section pile, and according to the difference of pile-forming process it includes the forms of extruding expansion into disk, rotating expansion into disk and drilling expansion into disk. The concrete expanding pile has high bearing capacity and strong pulling resistance and horizontal force resistance, so the concrete expanding pile is rapidly developed in recent years. However, the existing research is basically finite element simulation analysis and assists a small amount of field test verification, and the traditional research method cannot really see the damage condition of the soil body around the pile, so that the reliability of the research conclusion of the variable cross-section pile such as a concrete expanded-plate pile is influenced.

The subject group has invented a method for a laboratory small-scale model soil burying test of a concrete half-face pile, and the method has unique advantages in many aspects, such as flexible design, simple and convenient operation, cost saving, capability of observing the soil destruction process around the pile in the whole process, and the like. However, in the small-scale model soil burying test, the manufacturing of the pile soil test piece is completed by burying soil layer by layer in the test process, and the real condition of the soil body and other aspects are different from the actual condition inevitably, so that data information obtained by the test has certain deviation, and the final analysis result is influenced. Inspired by the soil sampling method of the surveying department, the subject group invents an undisturbed soil model test method which can pick undisturbed soil on site and manufacture small model test pieces under the condition of not damaging the soil body properties. The method can fulfill the aim of the original small model half-pile test, namely clearly observe and record the real situation of the joint work of the pile and the soil body under the condition that the pile is pressed and collect the relevant data information of stress, strain, settlement and the like, simultaneously can ensure the original state of the soil body, and provides objective and real data for the theoretical analysis of the concrete expansion pile. However, in the actual use process, the soil sampler has higher precision requirement, the operation processes of embedding the test piece after soil sampling in the test, inserting glass and the like have higher requirements, if the operation processes are careless, the soil sampler has small-amplitude deformation, the glass can not be inserted, and the soil structure is easily damaged in the glass inserting and pulling processes, so that the pile-soil joint surface is damaged and the like, and the test process and the test result are influenced.

Disclosure of Invention

The invention aims to provide a method for performing an undisturbed soil model test on a half-pile by using a detachable soil sampler, so that the operation is more convenient, and a pile-soil joint surface is not influenced.

The technical scheme for solving the technical problem is completed by the following steps:

(1) manufacturing a soil sampler, wherein the soil sampler consists of two plane plates and two side plates, the two edges of each side plate are provided with folding edges which are outward 90 degrees, the folding edges are provided with screw holes, the two edges of each plane plate are provided with reserved holes, the reserved holes correspond to the screw holes one by one, bolts penetrate through the reserved holes and the screw holes to fixedly connect the plane plates and the side plates, a bottomless and uncovered box body is formed, the plane plates and the side plates can be steel plates, the outer sides of the lower sides of the steel plates are cut into slope shapes, and the soil sampler can conveniently enter soil when being pressed in;

(2) after a test field is determined, according to a geological survey report, excavating the field to reach a soil layer needing soil taking;

(3) coating a thin layer of lubricating oil on the inner side of the soil sampler, then sequentially placing the soil sampler at the position of the soil layer of the excavated field, and pressing the soil sampler into the soil layer one by one through a pressure device;

(4) digging the soil around the soil sampler, and taking out the pressed soil sampler;

(5) removing the floating soil on the upper surface and the lower surface of the soil sampler, leveling the upper surface and the lower surface to form a soil sample test piece, wrapping the whole test piece by using plastic cloth to prevent water in the soil from losing, and transporting the test piece back to a test room;

(6) before the test is started, the plastic cloth wrapping the test piece is opened, one side of the soil sample test piece, which is required to be embedded into the model pile, is upward, namely the plane plate on one side is upward, and in order to avoid deformation of the soil sampler after the steel plate on one side is detached, the side plate of the soil sampler is fixed by a fixing iron clamp;

(7) detaching the bolt between the upward plane plate and the side plate, taking down the upward plane plate, and leveling the surface of the soil sample;

(8) placing one side of the plane of the manufactured half-face pile model on the surface of the leveled soil sample, and drawing the position and the size of the half-face pile model on the surface of the soil sample;

(9) digging a small groove of a half-face pile model on the surface of the soil sample according to the size of the drawn pile model, aligning one side of the cylindrical surface of the half-face pile model with the position of the small groove, and pressing in to manufacture a pile soil test piece;

(10) the glass plate is placed on the pile soil surface of the pressed half-face pile model, the glass and the soil sampler lacking the plane plate on one side are fixed by the fixing iron clamp, so far, the preparation of the pile soil test piece of the half-face pile undisturbed soil model test is completed, and the test piece can be placed on a test bed for a loading test.

The invention can conveniently bury the pile model because the soil sampler is detachable while finishing the target of taking the undisturbed soil on site, and the pile is accurately positioned by adopting a grooving mode, the visible glass surface is fixed by adopting a clamping mode, the operation is very simple and convenient, the detailed treatment is emphasized in each operation process of the test piece manufacture so as to ensure the good effect of the manufactured test piece and well ensure the reliability of the test result.

Drawings

FIG. 1 is a top view of a geotome;

FIG. 2 is a half sectional view of the geotome;

FIG. 3 is a schematic view of the soil sampler after being fixed by a fixing iron clamp.

Detailed Description

The invention is completed by the following steps:

1. manufacturing a soil sampler, wherein the soil sampler consists of two plane plates 1 and two side plates 2, the two edges of each side plate 2 are provided with a folding edge 3 with an outward 90-degree angle, the folding edge 3 is provided with a screw hole 4, the two edges of each plane plate 1 are provided with preformed holes 5, the preformed holes 5 correspond to the screw holes 4 one by one, bolts 6 penetrate through the preformed holes 5 and the screw holes 4 to fixedly connect the plane plates 1 and the side plates 2 to form a box body without a bottom and a cover, the plane plates 1 and the side plates 2 can be steel plates, the outer sides of the lower edges of the steel plates are cut into slope shapes, and the soil sampler can conveniently enter soil when pressed in;

2. after a test field is determined, according to a geological survey report, excavating the field to reach a soil layer needing soil taking;

3. coating a thin layer of lubricating oil on the inner side of the soil sampler, then sequentially placing the soil sampler at the position of the soil layer of the excavated field, and pressing the soil sampler into the soil layer one by one through a pressure device;

4. digging the soil around the soil sampler, and taking out the pressed soil sampler;

5. removing the floating soil on the upper surface and the lower surface of the soil sampler, leveling the upper surface and the lower surface to form a soil sample test piece, wrapping the whole test piece by using plastic cloth to prevent water in the soil from losing, and transporting the test piece back to a test room;

6. before the test is started, the plastic cloth wrapping the test piece is opened, one side of the soil sample test piece, which is required to be embedded into the model pile, is upward, namely the plane plate on one side is upward, and in order to avoid deformation of the soil sampler after the steel plate on one side is detached, the side plate of the soil sampler is fixed by a fixing iron clamp;

7. detaching the bolt between the upward plane plate and the side plate, taking down the upward plane plate, and leveling the surface of the soil sample;

8. placing one side of the plane of the manufactured half-face pile model on the surface of the leveled soil sample, and drawing the position and the size of the half-face pile model on the surface of the soil sample;

9. digging a small groove of a half-face pile model on the surface of the soil sample according to the size of the drawn pile model, aligning one side of the cylindrical surface of the half-face pile model with the position of the small groove, and pressing in to manufacture a pile soil test piece;

10. the glass plate is placed on the pile soil surface of the pressed half-face pile model, the glass and the soil sampler lacking the plane plate on one side are fixed by the fixing iron clamp, so far, the preparation of the pile soil test piece of the half-face pile undisturbed soil model test is completed, and the test piece can be placed on a test bed for a loading test.

Claims

1. A method for performing an undisturbed soil model test of a half-pile by using a detachable soil sampler is characterized by comprising the following steps:

(1) manufacturing a soil sampler, wherein the soil sampler consists of two plane plates and two side plates, the two edges of each side plate are provided with folding edges which are outward 90 degrees, the folding edges are provided with screw holes, the two edges of each plane plate are provided with preformed holes, the preformed holes correspond to the screw holes one by one, and bolts penetrate through the preformed holes and the screw holes to fixedly connect the plane plates and the side plates to form a box body without a bottom and a cover; the plane plate and the side plate are steel plates, and the outer side of the lower side of each steel plate is cut into a slope shape, so that the soil sampler can conveniently enter soil when pressed in;

(3) coating a layer of lubricating oil on the inner side of the soil sampler, placing the soil sampler at the position of the soil layer of the excavated field, and pressing the soil sampler into the soil layer;

(4) digging the soil around the soil sampler, and then taking out the soil sampler pressed in;

(5) removing the floating soil on the upper surface and the lower surface of the soil sampler, leveling the upper surface and the lower surface to form a soil sample test piece, wrapping the whole test piece by using plastic cloth, and transporting the whole test piece back to a test room;

(6) before the test is started, opening the plastic cloth wrapping the test piece, enabling one side of the soil sample test piece, which is required to be embedded into the model pile, to be upward, namely enabling a plane plate on one side to be upward, and fixing the side plate of the soil sampler by using a fixing iron clamp;

(9) digging a groove of a half-face pile model on the surface of the soil sample according to the size of the drawn pile model, aligning one side of the cylindrical surface of the half-face pile model with the groove position, and pressing in the groove to manufacture a pile soil test piece;

(10) and (3) placing a glass plate on the pile soil surface of the pressed half-face pile model, fixing the glass and the soil sampler lacking the plane plate on one side by using a fixing iron clamp, so far, completing the preparation of the pile soil test piece of the half-face pile undisturbed soil model test, and placing the pile soil test piece on a test bed for a loading test.