Method for simultaneously measuring pile-soil deformation of composite foundation under load test

Abstract

The present application relates to a load test method for measuring pile-soil deformation of a composite foundation in real time, which comprises the following steps: step 1, setting a pile in the foundation soil to construct a composite foundation; step 2, placing a pile gauge and a soil gauge on the surface of the composite foundation, so that the flat plate of the pile gauge is located on the top of the pile and the vertical column of the pile gauge is vertically upward, and so that the flat plate of the soil gauge is located on the surface of the foundation soil and the vertical column of the soil gauge is vertically upward; step 3, laying a cushion layer on the surface of the foundation soil, so that the flat plate of the pile gauge and the flat plate of the soil gauge are covered by the cushion layer, and so that the vertical column of the pile gauge and the vertical column of the soil gauge both pass through the cushion layer; step 4, pressing a pressure plate on the cushion layer, so that the vertical column of the pile gauge and the vertical column of the soil gauge both pass through the corresponding through hole of the pressure plate; arranging displacement measuring devices for the vertical column of the pile gauge and the vertical column of the soil gauge; step 5, applying pressure to the pressure plate by a pressure loading machine, and measuring the displacement of each vertical column, wherein the displacement obtained from the vertical column of the pile gauge is the pile settlement, and the displacement obtained from the vertical column of the soil gauge is the foundation soil settlement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foundation engineering test and detection of construction engineering, and particularly discloses a load test method for simultaneously measuring pile-soil deformation of composite foundation. BACKGROUND

[0002] At present, in order to study the stress mechanism and deformation law of the composite foundation, it is necessary to simultaneously measure the deformation of each part of the composite foundation under stress, including the deformation of the composite foundation, the deformation of the top surface of the subsoil under the cushion layer of the composite foundation, and the deformation of the pile top in the composite foundation. During the load test of the composite foundation, the deformation of the composite foundation is the deformation of the top surface of the bearing plate, and the measurement method is mature and simple. However, the deformation of the pile top and the top surface of the soil between piles under the bottom surface of the cushion layer, especially the deformation of the pile top, is relatively difficult to measure. At present, there is no clear method to regulate how to perform such work. If the operation is improper or unscientific, the measurement result will inevitably be inaccurate. SUMMARY

[0003] The present application aims to provide a method, that is, a small perforation is arranged on a bearing plate in a load test, a circular steel plate (a square steel plate can also be used for a square pile) is placed on the pile top at the center of the bottom surface of the cushion layer of the composite foundation, a round steel bar is welded on the side surface of the steel plate, a square or circular steel plate is placed on the top surface of the soil between piles at the bottom surface of the cushion layer of the composite foundation, a round steel bar is welded at the center position, the round steel bar passes through the reserved perforation on the bearing plate and rises above the bearing plate, and a measuring instrument for measuring the deformation of the pile top and the soil between piles is placed, the deformation of the top of the round steel bar is measured, the deformation of the pile top and the soil between piles can be obtained, the deformation of the top surface of the bearing plate can be measured, the deformation of each part of the composite foundation can be simultaneously measured, the deformation of the top of the steel bar represents the deformation of the soil between piles and the pile top, the deformation of the top surface of the bearing plate represents the deformation of the composite foundation and the top surface of the cushion layer.

[0004] Technical scheme: the load test method for simultaneously measuring pile-soil deformation of the composite foundation, which uses a pile measuring ruler, a soil measuring ruler, a bearing plate, a displacement measuring device and a pressure loading machine; the pile measuring ruler has a flat plate part, and at least two vertical columns are fixed on the upper surface of the flat plate part; the soil measuring ruler has a flat plate part, and a vertical column is fixed on the center of the upper surface of the flat plate part; the bearing plate is provided with a plurality of through holes, and the through holes are in one-to-one correspondence with the vertical columns of the pile measuring ruler and the soil measuring ruler and are in clearance fit; the method comprises the following steps:

[0005] Step 1: setting a pile in the subsoil to construct a composite foundation;

[0006] Step 2, place the pile gauge and the soil gauge on the surface of the composite foundation, so that the flat part of the pile gauge is on the top of the pile, and the vertical column of the pile gauge is vertically upward; so that the flat part of the soil gauge is on the surface of the foundation soil, and the vertical column of the soil gauge is vertically upward;

[0007] Step 3, lay the cushion layer on the surface of the composite foundation, so that the cushion layer covers the surface of the foundation soil, the flat part of the pile gauge and the flat part of the soil gauge, and so that the vertical column of the pile gauge and the vertical column of the soil gauge both pass out of the cushion layer;

[0008] Step 4, press the pressure plate on the cushion layer, so that the vertical column of the pile gauge and the vertical column of the soil gauge both pass out of the corresponding through hole of the pressure plate; and set a displacement measuring device for the vertical column of the pile gauge and the vertical column of the soil gauge;

[0009] Step 5, apply pressure to the pressure plate by the pressure loading machine, measure the displacement of each vertical column, the displacement obtained from the vertical column of the pile gauge is the pile settlement, and the displacement obtained from the vertical column of the soil gauge is the foundation soil settlement.

[0010] Further, all the vertical columns are made of metal, and the flat part of the pile gauge and the flat part of the soil gauge are also made of metal.

[0011] Further, the vertical column of the pile gauge is two, and is symmetrically distributed with respect to the center of the flat part of the pile gauge.

[0012] Further, the displacement measuring device comprises a dial indicator.

[0013] Further, there is a gap between the through hole of the pressure plate and the corresponding vertical column.

[0014] Further, the vertical column of the pile gauge and the vertical column of the soil gauge are stepped shafts, and the large end of the stepped shaft is located at the lower part, and the small end is located at the upper part. More preferably, the height of the large end of the stepped shaft is greater than the thickness of the pressure plate and the cushion layer as a whole.

[0015] Further, the vertical column of the soil gauge is located at the center of the corresponding flat part.

[0016] Further, each vertical column corresponds to a displacement measuring device.

[0017] Technical effect: the settlement deformation of the composite foundation, the pile and the soil between piles in the stress process of the composite foundation can be measured at the same time by a relatively simple method, low cost and a relatively reliable and accurate method. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a test schematic diagram of the present application;

[0019] Figure 2 is a schematic diagram of the position of the through hole of the bearing plate;

[0020] Figure 3 is a schematic diagram of the structure of the pile gauge;

[0021] Figure 4 is a schematic diagram of the structure of the soil gauge;

[0022] Figure 5 is a schematic diagram of the gap between the hole of the bearing plate and the vertical column;

[0023] Wherein: 1-pile, 2-ground soil, 3-pile gauge, 4-soil gauge, 5-bearing plate, 6-mattress layer, 7-displacement measuring device, 8-pressure loading machine, 9-through hole, 3a-flat plate part, 4a-flat plate part, 3b-vertical column, 4b-vertical column. DETAILED DESCRIPTION

[0024] Referring to the drawings Figure 1 Specifically provided is a load test method for simultaneously measuring the deformation of a pile-soil of a composite foundation, which uses a pile gauge, a soil gauge, a bearing plate, a displacement measuring device and a pressure loading machine; the pile gauge has a flat plate part, and at least two vertical columns are fixed on the upper surface of the flat plate part; the soil gauge has a flat plate part, and a vertical column is fixed at the center of the upper surface of the flat plate part; the bearing plate has a plurality of through holes, and the through holes correspond to the vertical columns of the pile gauge and the soil gauge one by one and are gap-fitted; the method comprises the following steps:

[0025] Step 1, setting the pile in the ground soil to construct a composite foundation;

[0026] Step 2, placing the pile gauge and the soil gauge on the surface of the composite foundation, so that the flat plate part of the pile gauge is located on the top of the pile, and the vertical columns of the pile gauge are vertically upward; so that the flat plate part of the soil gauge is located on the surface of the ground soil, and the vertical column of the soil gauge is vertically upward;

[0027] Step 3, laying the mattress layer on the surface of the ground soil, so that the flat plate part of the pile gauge and the flat plate part of the soil gauge are covered by the mattress layer, and the vertical columns of the pile gauge and the soil gauge both pass through the mattress layer;

[0028] Step 4, pressing the bearing plate on the mattress layer, so that the vertical columns of the pile gauge and the soil gauge both pass through the corresponding through holes of the bearing plate; setting the displacement measuring device for the vertical columns of the pile gauge and the soil gauge;

[0029] Step 5, applying pressure to the bearing plate by the pressure loading machine, and measuring the displacement of each vertical column; the displacement obtained from the vertical columns of the pile gauge is the pile settlement, and the displacement obtained from the vertical column of the soil gauge is the ground soil settlement.

[0030] All vertical columns are metal, and the flat plate part of the stake gauge and the flat plate part of the soil gauge are metal.

[0031] The vertical column of the stake gauge is two, and is symmetrically distributed relative to the center of the flat plate part of the stake gauge.

[0032] The displacement measuring device comprises a dial gauge.

[0033] There is a gap between the through hole of the pressure bearing plate and the corresponding vertical column.

[0034] The vertical column of the stake gauge and the soil gauge is a stepped shaft, and the large end of the stepped shaft is located at the lower part, and the small end is located at the upper part. The height of the large end of the stepped shaft is greater than the thickness of the whole pressure bearing plate and the cushion layer.

[0035] The vertical column of the soil gauge is located at the center of the corresponding flat plate part. Each vertical column corresponds to a displacement measuring device.

Claims

1. A method of load testing a composite ground pile-soil deformation by time measurement, characterized by: The method uses a pile gauge, a soil gauge, a pressure plate, a displacement measuring device and a pressure loading machine; the pile gauge has a flat plate, and at least two vertical columns are fixed on the upper surface of the flat plate; the soil gauge has a flat plate, and a vertical column is fixed at the center of the upper surface of the flat plate; the pressure plate has a plurality of through holes, and the plurality of through holes correspond to the vertical columns of the pile gauge and the soil gauge in a one-to-one manner and are in clearance fit; the method comprises the following steps: Step 1, setting the pile in the foundation soil to construct a composite foundation; Step 2, placing the pile gauge and the soil gauge on the surface of the composite foundation, so that the flat plate of the pile gauge is located on the top of the pile, and the vertical column of the pile gauge is vertically upward; so that the flat plate of the soil gauge is located on the surface of the foundation soil, and the vertical column of the soil gauge is vertically upward; Step 3, laying a cushion layer on the surface of the composite foundation, so that the cushion layer covers the surface of the foundation soil, the flat plate of the pile gauge and the flat plate of the soil gauge, and the vertical column of the pile gauge and the vertical column of the soil gauge both pass through the cushion layer; Step 4, pressing the pressure plate on the cushion layer, so that the vertical column of the pile gauge and the vertical column of the soil gauge both pass through the corresponding through hole of the pressure plate; the displacement measuring device is arranged corresponding to the vertical column of the pile gauge and the vertical column of the soil gauge; Step 5, applying pressure to the pressure plate by the pressure loading machine, measuring the displacement of each vertical column, the displacement obtained from the vertical column of the pile gauge is the pile settlement, and the displacement obtained from the vertical column of the soil gauge is the foundation soil settlement.

2. The load test method for measuring deformation of a composite ground pile-soil according to claim 1, characterized in that: All vertical columns are made of metal, and the flat plate of the pile gauge and the flat plate of the soil gauge are also made of metal.

3. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: The vertical column of the pile gauge has two columns, which are symmetrically distributed with respect to the center of the flat plate of the pile gauge.

4. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: The displacement measuring device is a displacement measuring dial indicator.

5. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: There is a gap between the through hole of the pressure plate and the corresponding vertical column.

6. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: The vertical column of the pile gauge and the vertical column of the soil gauge are stepped shafts, and the large end of the stepped shaft is located at the lower part, and the small end is located at the upper part.

7. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: The height of the large end of the stepped shaft is greater than the thickness of the pressure plate and the cushion layer as a whole.

8. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: The vertical column of the soil gauge is located at the center of the corresponding flat plate.

9. The load test method for measuring deformation of a composite ground pile-soil according to claim 1 or 2, characterized in that: Each vertical column corresponds to a displacement measuring device.

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