Method for testing proportionality coefficient of horizontal resistance coefficient of deep rock-soil body

Abstract

The invention relates to the technical field of civil engineering, in particular to a method for testing a proportionality coefficient of a horizontal resistance coefficient of a deep rock-soil body, which comprises the following steps of: drilling two test holes with the diameter of D and the depth of H from the ground according to geological exploration data and the depth of a build-in layer required by design; dowel bars with sleeves are inserted into the test holes respectively, and cement paste is poured between the sleeve of the built-in section and the test holes; a jack is installed between the tops of the two dowel bars, and a displacement monitoring dial indicator is installed at the stress point of each dowel bar; applying a load to the dowel bar by adopting a low-speed load maintaining method until the horizontal displacement of the dowel bar on the ground reaches delta + 40mm or delta + Y0mm; recording the reading of the dial indicator in the step S3 under the load applied in the step S4, and calculating the horizontal resistance coefficient proportionality coefficient of the rock-soil body by converting the horizontal displacement Y0 of the starting point of the built-in section; the method is simple, convenient and rapid in testing, low in cost and capable of effectively providing a basis for design of the anti-slide pile, so that the designed anti-slide pile is safer, more economical and more applicable.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a method for testing a proportional coefficient of a horizontal resistance coefficient of a deep rock and soil body. Background Art

[0002] Civil engineering is a general term for the science and technology of building various types of land engineering facilities; it refers to the materials and equipment used, as well as the technical activities such as survey, design, construction, maintenance and repair carried out, as well as the objects of engineering construction, including houses, roads, railways, pipelines, tunnels, bridges, canals, dams, ports, power stations, airports, offshore platforms, water supply and drainage, and protective projects. The proportional coefficient value of the horizontal resistance coefficient of rock and soil mass is an important parameter in the design of anti-slide pile support in civil engineering. Its value directly affects the safety, applicability and economy of the support structure.

[0003] However, the existing methods can only test the m-value of rock and soil within a certain depth range near the surface, and most of the existing testing means use special test piles or engineering piles for testing, which have high pile costs, long testing time, poor economy, and cannot test the m-value of deep rock and soil of anti-sliding piles. Therefore, in the design process of anti-sliding piles, no relevant m-value test is carried out for specific engineering projects, and the value of m is mainly determined by referring to the empirical value given in relevant standards; the regional differences in rock and soil are very large, and engineering practice shows that the empirical value of m given in the standard is often very different from the rock and soil characteristics of actual projects. Designing support structures according to the empirical value given in the standard may result in insufficient safety or low economy. Summary of the invention

[0004] The purpose of the present invention is to provide a method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil, so as to solve the problem that the existing methods in the prior art can only test the m value of the rock and soil within a certain depth range near the surface, and the existing testing means mostly use special test piles or engineering piles for testing, which has high pile cost, long testing time, poor economy, and cannot test the m value of the deep rock and soil of the anti-sliding pile. Therefore, in the design process of anti-sliding piles, relevant m value tests are not carried out for specific engineering projects, and the value of m is mainly determined by referring to the empirical value given by relevant standards; the regional differences of rock and soil are very large, and engineering practice shows that the m empirical value given by the standard is often very different from the rock and soil characteristics of the actual project. The support structure design based on the empirical value given by the standard may have technical problems such as insufficient safety or low economy.

[0005] To achieve the above object, the present invention provides a method for testing the proportional coefficient of the horizontal resistance coefficient of a deep rock and soil mass, the method comprising the following steps:

[0006] S1: Drill two test holes with a diameter of D and a depth of H according to the geological survey data of the rock and soil area to be tested and the embedded layer depth required by the design;

[0007] S2: Insert the force transmission rod with sleeve into the test hole respectively, and pour cement slurry between the sleeve of the embedded section and the test hole;

[0008] S3: Install the jack between the tops of the two force transmission rods, and install a displacement monitoring dial indicator at the force transmission rod force point;

[0009] S4: Use the slow load maintenance method to apply load to the dowel rod until the horizontal displacement of the dowel rod on the ground reaches Δ+40mm or Δ+Y0mm, and then terminate the loading;

[0010] S5: Record the reading of the dial gauge in S3 under the load applied by S4, and obtain the horizontal displacement Y0 of the starting point of the embedded section by conversion, so as to calculate the proportional coefficient m of the horizontal resistance coefficient of the rock and soil mass;

[0011] S6: After the test, remove the dowel rod from the sleeve for reuse.

[0012] Wherein, in step S1, the hole depth enters the designed embedding section h1, and h1 is not less than 1m, and the distance between the two holes is 5D.

[0013] Wherein, in step S2, the force transmission rod is tightly connected to the sleeve, the sleeve is located at the bottom of the force transmission rod, and the length of the sleeve is 1m.

[0014] Wherein, in step S2, the sleeve is in close contact with the hole wall of the test hole, and the distance between the outer wall of the force transmission rod and the hole wall of the test hole is greater than Δ+40 mm.

[0015] Wherein, in step S2, during the test, the force transmission rod and the rock and soil of the hole wall of the test hole do not contact each other.

[0016] Among them, in step S4, the two force transmission rods react against each other, and Y0 is the allowable value of horizontal displacement of the starting point of the embedded section required by the design.

[0017] Wherein, in step S5, the starting point of the embedding section is the top of the sleeve.

[0018] The invention discloses a method for testing the proportional coefficient of the horizontal resistance coefficient of a deep rock and soil body. According to the geological survey data of the rock and soil body area to be tested and the embedded layer depth required by the design, two test holes with a diameter of D and a depth of H are drilled from the ground; a dowel rod with a sleeve is inserted into each of the test holes, and cement slurry is poured between the embedded sleeve and the test hole; a jack is installed between the tops of the two dowel rods, and a displacement monitoring dial gauge is installed at the force point of the dowel rod; a slow load maintenance method is used to apply a load to the dowel rod until the horizontal displacement of the dowel rod on the ground reaches Δ+40m. m or Δ+Y0mm; record the dial indicator reading in S3 under the load applied by S4, and obtain the horizontal displacement Y0 of the starting point of the embedded section by conversion, so as to calculate the proportional coefficient m of the horizontal resistance coefficient of the rock and soil mass; after the test, take out the force transmission rod from the sleeve for reuse. The present invention can effectively solve the problem that the existing method cannot test the proportional coefficient of the horizontal resistance coefficient of the deep rock and soil mass. At the same time, the method is simple, fast and low-cost to test, and can effectively provide a basis for the design of anti-slide piles, so that the designed anti-slide piles are safer, more economical and more applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a flow chart of the steps of the proportional coefficient testing method of the horizontal resistance coefficient of deep rock and soil body of the present invention.

[0021] Figure 2 It is a structural schematic diagram of the test device in the present invention.

[0022] Figure 3 It is a structural schematic diagram of the force transmission rod of the test device in the present invention.

[0023] Figure 4 A schematic structural diagram of a steel sleeve of the test device of the present invention. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] See also Figure 1 to Figure 4The present invention provides a method for testing the proportional coefficient of the horizontal resistance coefficient of a deep rock and soil mass, and the method comprises the following steps:

[0026] S1: Drill two test holes with a diameter of D and a depth of H according to the geological survey data of the rock and soil area to be tested and the depth of the embedded layer required by the design;

[0027] S2: Insert the force transmission rod with sleeve into the test hole respectively, and pour cement slurry between the sleeve of the embedded section and the test hole;

[0028] S3: Install the jack between the tops of the two force transmission rods, and install a displacement monitoring dial indicator at the force transmission rod force point;

[0029] S4: Use the slow load maintenance method to apply load to the dowel rod until the horizontal displacement of the dowel rod on the ground reaches Δ+40mm or Δ+Y0mm, and then terminate the loading;

[0030] S5: Record the reading of the dial gauge in S3 under the load applied by S4, and obtain the horizontal displacement Y0 of the starting point of the embedded section by conversion, so as to calculate the proportional coefficient m of the horizontal resistance coefficient of the rock and soil mass;

[0031] S6: After the test, remove the dowel rod from the sleeve for reuse.

[0032] In this embodiment, the present invention can effectively solve the problem that the existing methods cannot test the proportional coefficient of the horizontal resistance coefficient of deep rock and soil. At the same time, this method is simple, fast, and low-cost to test, and can effectively provide a basis for the design of anti-slide piles, making the designed anti-slide piles safer, more economical, and more applicable.

[0033] Wherein, in step S1, the hole depth enters the designed embedding section h1, and h1 is not less than 1m, and the distance between the two holes is 5D.

[0034] Wherein, in step S2, the force transmission rod is tightly connected to the sleeve, the sleeve is located at the bottom of the force transmission rod, and the length of the sleeve is 1m.

[0035] Wherein, in step S2, the sleeve is in close contact with the hole wall of the test hole, and the distance between the outer wall of the force transmission rod and the hole wall of the test hole is greater than Δ+40 mm.

[0036] In this embodiment, the calculation formula of Δ is as follows:

[0037]

[0038] F——horizontal force acting on the top of the force transmission rod, in kN;

[0039] h2——the vertical distance from the F action point to the starting point of the embedded section, in m;

[0040] E1I1——Bending stiffness of dowel rod, in kN / m 2 ;

[0041] E1 is the elastic modulus of the dowel rod material;

[0042] I1 is the moment of inertia of the force transmission rod section.

[0043] Wherein, in step S2, during the test, the force transmission rod and the rock and soil of the hole wall of the test hole do not contact each other.

[0044] Among them, in step S4, the two force transmission rods react against each other, and Y0 is the allowable value of horizontal displacement of the starting point of the embedded section required by the design.

[0045] In this embodiment, the calculation formula of m is as follows:

[0046]

[0047] m——Proportional coefficient of horizontal resistance coefficient of foundation soil, unit is kN / m 4 ;

[0048] V y ——horizontal displacement coefficient of the starting point of the embedded section;

[0049] F——horizontal force acting on the top of the force transmission rod, in kN;

[0050] Y0——horizontal displacement of the starting point of the embedded section, in m;

[0051] E2I2——Bending stiffness of sleeve, in kN / m 2 ;

[0052] E2 is the elastic modulus of the sleeve material;

[0053] I2 is the converted section moment of inertia of the sleeve;

[0054] b0——Calculated width of the sleeve, in m. When the sleeve diameter d2≤1m, b0=0.9(1.5d2+0.5).

[0055] The invention provides a method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil. The testing method is simple and quick, the testing device can be recycled and reused, and the method has good economic and applicable value.

[0056] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for testing the proportional coefficient of horizontal resistance coefficient of deep rock and soil mass, characterized in that: The steps include: S1: Drill two test holes with a diameter of D and a depth of H according to the geological survey data of the rock and soil area to be tested and the embedded layer depth required by the design; S2: Insert the force transmission rod with sleeve into the test hole respectively, and pour cement slurry between the sleeve of the embedded section and the test hole; S3: Install the jack between the tops of the two force transmission rods, and install a displacement monitoring dial indicator at the force transmission rod force point; S4: Use the slow load maintenance method to apply load to the dowel rod until the horizontal displacement of the dowel rod on the ground reaches Δ+40mm or Δ+Y0mm, and then terminate the loading; S5: Record the reading of the dial gauge in S3 under the load applied by S4, and obtain the horizontal displacement Y0 of the starting point of the embedded section by conversion, so as to calculate the proportional coefficient m of the horizontal resistance coefficient of the rock and soil mass; S6: After the test, remove the dowel rod from the sleeve for reuse.

2. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 1, characterized in that: In step S1, the hole depth enters the designed embedding section h1, and h1 is not less than 1m, and the distance between the two holes is 5D.

3. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 2, characterized in that: In step S2, the dowel rod is tightly connected to the sleeve, the sleeve is located at the bottom of the dowel rod, and the length of the sleeve is 1 m.

4. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 3, characterized in that: In step S2, the sleeve is in close contact with the hole wall of the test hole, and the distance between the outer wall of the force transmission rod and the hole wall of the test hole is greater than Δ+40 mm.

5. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 4, characterized in that: In step S2, during the test, the force transmission rod and the rock and soil of the test hole wall do not contact each other.

6. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 5, characterized in that: In step S4, the two force transmission rods react against each other, and Y0 is the allowable value of horizontal displacement of the starting point of the embedded section required by the design.

7. The method for testing the proportional coefficient of the horizontal resistance coefficient of deep rock and soil mass according to claim 6, characterized in that: In step S5, the starting point of the embedding section is the top of the sleeve.

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