A design method for protective measures of buildings / structures near foundation pits

Abstract

The present invention discloses a method for designing protective measures for buildings / structures adjacent to a foundation pit, comprising the following steps: S1, designing reasonable protective measure factors; S2, adding new factors for strengthening protective measures; S3, selecting n main factors for strengthening protective measures with larger levee sensitivity coefficients; S4, determining test control indicators; S5, performing range analysis, performing range analysis on the test control indicators obtained in S4, eliminating protective measure factors with the smallest impact on the test control indicators, and retaining the remaining protective measure factors; S6, establishing an objective function for project cost, and determining optimal protective measures. According to the method of the present invention, design measures that are most conducive to controlling buildings / structures around the foundation pit can be quickly obtained.

Description

Technical Field

[0001] The present invention relates to the field of design of protective measures for buildings / structures adjacent to foundation pits, and more particularly to a design method of protective measures for buildings / structures adjacent to foundation pits. Background Art

[0002] The main protective design measures for buildings (structures) near foundation pits include strengthening the rigidity of the retaining structure and setting up isolation piles. However, there is currently no standard for the combined effect of several protective measures, making it impossible to conduct specific analysis based on different situations, and economic efficiency is not considered in the design. Summary of the Invention

[0003] To achieve these objectives and other advantages according to the present invention, a method for designing protective measures for buildings / structures adjacent to foundation pits is provided, comprising the following steps:

[0004] S1. Design of reasonable protective measures

[0005] Determine the protective measures for buildings / structures and use rational design software to design reasonable protective factors that affect the protective effect of the protective measures;

[0006] S2. Added factors to strengthen protective measures;

[0007] On the basis of the reasonable protective measures factors designed in S1, further strengthen the protective measures and add new strengthening protective measures factors accordingly;

[0008] S3. Select n main factors with larger levee sensitivity coefficients to strengthen protection measures

[0009] Calculate the average levee sensitivity coefficient under each enhanced protection measure factor, and finally select n main enhanced protection measure factors with larger levee sensitivity coefficients

[0010] S4. Determine the test control indicators

[0011] For the main factors of strengthening protective measures in S3, different values ​​representing high, medium and low values ​​were selected to conduct orthogonal experiments. The levee settlement, levee horizontal displacement and levee influence range under different working conditions were obtained by numerical calculation as experimental control indicators.

[0012] S5. Range Analysis

[0013] Perform range analysis on the test control indicators obtained from S4, eliminate the protective measure factors with the smallest impact on the test control indicators, and retain the remaining protective measure factors;

[0014] S6. Establish the objective function of project cost

[0015] The protective measures factors retained in S5 are used as variables to establish the objective function of project cost, and the Monte Carlo method is used to screen out the most economical combination that meets the levee deformation control standard, that is, the optimal protective measures.

[0016] According to a preferred embodiment of the present invention, the reasonable protective measures factors include steel sheet piles, steel support model, steel support spacing, and the number of steel support rows.

[0017] According to a preferred embodiment of the present invention, the factors for strengthening protective measures include steel sheet pile insertion ratio, steel sheet pile stiffness, steel support stiffness, isolation wall position, isolation wall thickness, and isolation wall depth.

[0018] According to a preferred embodiment of the present invention, in S3, calculating the average levee sensitivity coefficient under each enhanced protection measure factor specifically includes the following steps:

[0019] For each factor of enhanced protection measures, three different values ​​representing high, medium, and low were selected, and three different levee sensitivity coefficients were calculated using numerical calculation software. The average levee sensitivity coefficient under each enhanced protection measure factor was also calculated.

[0020] Among them, the levee sensitivity coefficient η is calculated by the following formula

[0021] η=s i / s;

[0022] Where s is the embankment settlement of the building / structure based on the reasonable protection measures in S1;

[0023] s i It is the embankment settlement of buildings / structures based on the reasonable protection measures factor in S1 and the enhanced protection measures factor in S2.

[0024] According to a preferred embodiment of the present invention, in S5, the range is calculated using the following formula:

[0025] Extremely poor Among them, K ij is the sum of the test indicators of factor number i and level j,

[0026] The present invention has at least the following beneficial effects: This method utilizes orthogonal testing to evaluate the combined effects of these measures and introduces an economic objective function to find the most economical solution that meets criteria such as building (structure) deformation. The method according to the present invention can quickly determine the design measures that are most effective in controlling the buildings (structures) surrounding the foundation pit.

[0027] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the steps of the method for designing protective measures for buildings / structures near foundation pits in the present invention. DETAILED DESCRIPTION

[0029] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0030] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0031] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0032] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0033] like Figure 1 As shown, a design method for protective measures for buildings / structures adjacent to foundation pits includes the following steps:

[0034] S1. Design protection factors

[0035] Determine the protective measures for buildings / structures and use rational design software to design reasonable protective factors that affect the protective effect of the protective measures;

[0036] The reasonable protective measures factors include steel sheet piles, steel support models, steel support spacing, and the number of steel support tracks.

[0037] This step is to determine the appropriate protective measures for the retaining structure that meet the requirements of the foundation pit. For example, the steel support model is calculated to be 609mm in diameter and 8mm thick, arranged in two rows, and the steel sheet pile model is Larsen III with an insertion ratio of 0.6.

[0038] S2. Added factors to strengthen protective measures;

[0039] On the basis of the reasonable protective measures factors designed in S1, further strengthen the protective measures and add new strengthening protective measures factors accordingly;

[0040] The factors for strengthening protective measures include steel sheet pile insertion ratio, steel sheet pile stiffness, steel support stiffness, isolation wall position, isolation wall thickness, and isolation wall depth.

[0041] S3. Select n main factors with larger levee sensitivity coefficients to strengthen protection measures

[0042] Calculate the average levee sensitivity coefficient under each enhanced protection measure factor, and finally select n main enhanced protection measure factors with the largest levee sensitivity coefficient;

[0043] In S3, the average levee sensitivity coefficient under each enhanced protection measure factor is calculated, which specifically includes the following steps:

[0044] For each factor of enhanced protection measures, three different values ​​representing high, medium, and low were selected, and three different levee sensitivity coefficients were calculated using numerical calculation software. The average levee sensitivity coefficient under each enhanced protection measure factor was also calculated.

[0045] Among them, the levee sensitivity coefficient η is calculated by the following formula

[0046] η=s i / s;

[0047] Where s is the embankment settlement of the building / structure based on the reasonable protection measures in S1;

[0048] s i It is the embankment settlement of buildings / structures based on the reasonable protection measures factor in S1 and the enhanced protection measures factor in S2.

[0049] In another technical solution, in S5, the range is calculated using the following formula:

[0050] Extremely poor Among them, K ij is the sum of the test indicators of factor number i and level j,

[0051] S4. Determine the test control indicators

[0052] For the main factors of strengthening protective measures in S3, different values ​​representing high, medium and low values ​​were selected to conduct orthogonal experiments. The levee settlement, levee horizontal displacement and levee influence range under different working conditions were obtained by numerical calculation as experimental control indicators.

[0053] For example, if the n main factors for strengthening protective measures are the stiffness of steel sheet piles, the type of steel support, and the thickness of the isolation wall, the orthogonal test is shown in the following table.

[0054] Table 1 Orthogonal test table

[0055]

[0056]

[0057] S5. Range Analysis

[0058] Perform range analysis on the test control indicators obtained from S4, eliminate the protective measure factors with the smallest impact on the test control indicators, and retain the remaining protective measure factors;

[0059] The test control indicators (levee settlement, levee horizontal deformation) were subjected to range analysis, as shown in the following table.

[0060] Table 2 Range method analysis calculation formula

[0061]

[0062] Extremely poor K ij is the sum of the test indicators of factor number i and level j.

[0063]

[0064] Such as K 12 The sum of the test indicators of Larsen III steel sheet piles, steel support diameter 630mm and thickness 16mm, and separation wall thickness of 0.8m, 1.0m, and 1.2m. ij If the K value of 1.0m ij and 1.2m K ij If the T value of a factor is larger, the influence of this factor on the index is greater. The protective measures with the smallest influence on both settlement deformation and horizontal deformation are eliminated, and the factors with the largest influence are retained.

[0065] S6. Establish the objective function of project cost

[0066] The protective measures factors retained in S5 are used as variables to establish the objective function of project cost, and the Monte Carlo method is used to screen out the most economical combination that meets the levee deformation control standard, that is, the optimal protective measures.

[0067] Specifically, the Monte Carlo method was used to screen the most economical combination that met the levee deformation control standards. Key factors included the stiffness of the steel sheet piles (equivalent thickness h1), the steel support type (diameter D, thickness h2), and the isolation wall thickness (h3). The length of the foundation pit was L, the width was B, the steel support spacing was s, the steel density was ρ, the monthly rental cost of the steel sheet piles was M1 / ton, and the cost of the protective wall was M2 / m 3 , the monthly rental fee of steel support is M3 / ton, and the use time of foundation pit is t (month). Then the objective function

[0068] f(h1, h2, h3, D)=L·H·(1+λ)·h1·ρ·M1+L·h3·H1·M2+2×π / 4×(D 2 -(D-2h2) 2 )·B·L / s·ρ·M3

[0069] Among them, the value ranges of h1, h2, h3, and D are determined according to step (4), H is the foundation pit depth, λ is the steel sheet pile insertion ratio, and H1 is the depth of the protective wall.

[0070] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A design method for protective measures for buildings / structures adjacent to foundation pits, characterized in that: The following steps are involved: S1. Design of reasonable protective measures Determine the protective measures for buildings / structures and use rational design software to design reasonable protective factors that affect the protective effect of the protective measures; S2. Added factors to strengthen protective measures; On the basis of the reasonable protective measures factors designed in S1, further strengthen the protective measures and add new strengthening protective measures factors accordingly; S3. Select n main factors with larger levee sensitivity coefficients to strengthen protection measures Calculate the average levee sensitivity coefficient under each enhanced protection measure factor, and finally select n main enhanced protection measure factors with the largest levee sensitivity coefficient; S4. Determine the test control indicators For the main factors of strengthening protective measures in S3, different values ​​representing high, medium and low values ​​were selected to conduct orthogonal experiments. The levee settlement, levee horizontal displacement and levee influence range under different working conditions were obtained by numerical calculation as experimental control indicators. S5. Range Analysis Perform range analysis on the test control indicators obtained from S4, eliminate the protective measure factors with the smallest impact on the test control indicators, and retain the remaining protective measure factors; S6. Establish the objective function of project cost and determine the best protective measures The protective measures factors retained in S5 are used as variables to establish the objective function of project cost, and the Monte Carlo method is used to screen out the most economical combination that meets the levee deformation control standard, that is, the optimal protective measures; The reasonable protective measures factors include steel sheet piles, steel support model, steel support spacing, and number of steel support tracks; The factors for strengthening protective measures include steel sheet pile insertion ratio, steel sheet pile stiffness, steel support stiffness, isolation wall position, isolation wall thickness, and isolation wall depth.

2. The design method for protective measures for buildings / structures adjacent to foundation pits according to claim 1 is characterized in that: In S3, the average levee sensitivity coefficient under each enhanced protection measure factor is calculated, which specifically includes the following steps: For each factor of enhanced protection measures, three different values ​​representing high, medium, and low were selected, and three different levee sensitivity coefficients were calculated using numerical calculation software. The average levee sensitivity coefficient under each enhanced protection measure factor was also calculated. Among them, the levee sensitivity coefficient η is calculated by the following formula the=s i / s; Where s is the embankment settlement of the building / structure based on the reasonable protection measures in S1; s i It is the embankment settlement of buildings / structures based on the reasonable protection measures factor in S1 and the enhanced protection measures factor in S2.

3. The design method for protective measures for buildings / structures adjacent to foundation pits according to claim 2, characterized in that: In S5, the range is calculated using the following formula: Extremely poor Among them, K ij is the sum of the test indicators of factor number i and level j,

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