CN-121350386-B - Finite soil body passive soil pressure calculation method considering narrow foundation pit space effect, storage medium and application

CN121350386BCN 121350386 BCN121350386 BCN 121350386BCN-121350386-B

Abstract

The invention relates to a method for calculating the passive soil pressure of a limited soil body taking the space effect of a narrow foundation pit into consideration, a storage medium and application thereof, comprising the steps of obtaining the calculation parameters of the narrow foundation pit, determining the increase coefficient of the space effect and obtaining the passive soil pressure of the soil body accounting for the space effect; the space effect increase coefficient is obtained based on a fitting formula, wherein the fitting formula is obtained by establishing a finite soil body passive soil wedge mechanical model, calculating the passive soil pressure of the finite soil body at different depths, further calculating the finite soil body passive soil pressure intensity, defining the ratio of the finite soil body passive soil pressure intensity to the improved Rankine passive soil pressure intensity as the space effect increase coefficient, drawing a space effect increase coefficient curve of different foundation pit widths, and establishing a fitting formula of the space effect increase coefficient. Compared with the prior art, the method can quantitatively evaluate the space effect accurately, further obtain more accurate passive soil pressure, can be used for optimizing the depth of the narrow foundation pit guard pile in soil, and has obvious engineering application value.

Inventors

ZHOU QING
ZHOU MIN
Suo Chaofeng
WANG TING
OUYANG GUOBIN

Assignees

同济大学建筑设计研究院(集团)有限公司

Dates

Publication Date: 20260505
Application Date: 20251217

Claims (4)

1. The method for calculating the passive soil pressure of the limited soil body by considering the space effect of the narrow foundation pit is characterized by comprising the following steps of: obtaining a narrow foundation pit calculation parameter, and determining a space effect increase coefficient according to the narrow foundation pit calculation parameter, wherein the narrow foundation pit calculation parameter comprises soil cohesive force, foundation pit width, fender pile penetration depth, an internal friction angle and pile soil external friction angle reduction coefficient; Multiplying the space effect increase coefficient in a passive soil pressure intensity formula of the improved Rankine method to obtain the soil passive soil pressure intensity accounting for the space effect, thereby obtaining the soil passive soil pressure; the spatial effect increase coefficient is obtained based on a fitting formula, and the obtaining of the fitting formula specifically comprises the following steps: Establishing a finite soil body passive soil wedge mechanical model, simulating and calculating the passive soil pressure of the finite soil body at different depths according to the mechanical model, calculating the finite soil body passive soil pressure intensity according to the passive soil pressure, and defining the ratio of the finite soil body passive soil pressure intensity obtained by simulation calculation to the improved Rankine passive soil pressure intensity as a space effect increase coefficient; drawing space effect increase coefficient curves with different foundation pit widths, introducing an ultra-deep critical ratio as an independent variable, merging the space effect increase coefficient curves with different foundation pit widths into one curve, and establishing a fitting formula of the space effect increase coefficient; when a fitting formula of the space effect increase coefficient is built, parameterizing the width of a foundation pit and the depth of the embedded pile into an ultra-deep face ratio, and building the fitting formula of the space effect increase coefficient into a function of the ultra-deep face ratio, an internal friction angle and a pile soil external friction angle reduction coefficient; The ultra-deep face ratio obtaining formula is as follows: , wherein h is the depth of the guard pile to be buried, b is the width of the foundation pit, 、 For the slip-face to face dip, Is an ultra-deep critical ratio; when the current soil body is judged to be non-cohesive soil based on the soil body cohesive force, a fitting formula of the space effect increase coefficient is as follows: In the coefficients 、、、 And B is the reduction coefficient of the internal friction angle phi and the external friction angle of the pile soil Is a function of (a) and (b), Is an ultra-deep critical ratio; When the current soil body is judged to be the cohesive soil based on the soil body cohesive force, the space effect increase coefficient comprises phi And item C Wherein: In the coefficients 、、、、 And B is the reduction coefficient of the internal friction angle phi and the external friction angle of the pile soil Is a function of (a) and (b), 、 To create a critical depth of slip planes; the expression of the soil body passive soil pressure intensity of the space effect is as follows: 。
2. the method for calculating the passive soil pressure of the limited soil body considering the space effect of the narrow foundation pit according to claim 1, wherein the calculation method satisfies the following assumption: a) The guard piles are rigid retaining walls, and translational displacement modes of the guard piles occur in the foundation pit; b) The soil body in the passive area generates a related broken line sliding surface; c) Each sliding crack surface reaches a passive limit state at the same time; d) Considering the external friction angle of the pile soil, neglecting the cohesive force between the pile soil.
3. A computer readable storage medium comprising one or more programs for execution by one or more processors of an electronic device, the one or more programs including instructions for performing the limited soil mass passive earth pressure calculation method of any of claims 1-2 that accounts for the effects of narrow foundation pit space.
4. The application of the limited soil body passive soil pressure calculation method considering the narrow foundation pit space effect in the pile penetration depth optimization based on the narrow foundation pit space effect, which is characterized in that anti-capsizing stable safety coefficients corresponding to different pile penetration depths are determined based on the calculated soil body passive soil pressure, so that the optimal pile penetration depth is obtained.

Description

Finite soil body passive soil pressure calculation method considering narrow foundation pit space effect, storage medium and application Technical Field The invention relates to the technical field of geotechnical engineering, in particular to a method for calculating the passive soil pressure of a limited soil body by considering the space effect of a narrow foundation pit, a storage medium and application. Background The anti-overturning stable safety coefficient is a key control index of the penetration depth of foundation pit supporting piles in soft soil areas. The current specification is based on classical soil pressure theory, and is simple to calculate but does not consider the beneficial effect of the narrow foundation pit space effect. Engineering practice shows that the smaller the foundation pit width is, the more obvious the space effect is, the smaller the deformation of the enclosure structure is, the better the stability is, and the shallower the required soil penetration depth is. The 10.2.3.3 th piece of DBJ08-61-97 of foundation pit engineering design rules of Shanghai city stipulates that the insertion ratio of the pipeline groove is 0.5-0.8, and a large amount of monitoring data verify the reliability of the pipeline groove. However, the 2010 version specification deletes the regulations, so that the soil penetration depth of the pipeline trench guard pile is greatly increased, waste is caused, and the adverse effect of the temporary steel sheet pile driving and pulling construction is increased. The width-depth ratio of the narrow foundation pit is small, and the basic assumption that the soil body in the passive area is a semi-infinite body in the classical soil pressure theory is not satisfied. In the limit state, the passive slip surface extends to the opposite side guard post, and the continuous calculation by the Rankine theory is obviously unreasonable. The existing research shows that the stability analysis method which is proposed in the early stage such as Terzaghi, peck and considers the width of the foundation pit has obvious limitation because the influence of the embedded section of the guard pile is not counted. The literature 'influence of foundation pit width on stability of building envelope' (Wang Hongxin. Civil engineering report, 2011, 44 (6): 120-126.) classifies foundation pits based on aspect ratio, and provides a corresponding anti-capsizing safety coefficient calculation method. But its deduction about the "trapezoidal passive soil wedge wedging effect" is based on rigid body assumption, ignoring secondary slip planes that may be generated inside the soil body, resulting in overestimation of the beneficial effect of the narrow foundation pit space effect on the overturning stability. Numerous scholars' studies on finite soil pressure theory have shown that classical Rankine or coulomb theory may bias the foundation pit design toward conservation. In the literature ' passive soil pressure analysis of a rigid retaining wall in a narrow foundation pit translation mode ' (to be applied to macroscopic. Rock-soil mechanics, 2011, 32 (12): 3755-3762.) ', a limited soil mass passive soil pressure calculation model of the narrow foundation pit is established based on coulomb plane soil wedge assumption, an associated broken line slip surface is generated in a passive region, and an analysis solution of a slip plane inclination angle and a passive soil pressure coefficient is deduced. Although the research has important progress in the aspect of soil pressure increasing mechanism, the calculation formula of the soil pressure increasing mechanism needs to be solved through complex iteration, and a small-scale model is adopted and the aspect ratio is taken as a main parameter, so that the soil pressure coefficient is concentrated in a steep-falling section of a curve, the quantitative relation between the soil pressure coefficient and a space effect is difficult to establish, and engineering application is limited. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a limited soil body passive soil pressure calculation method, a storage medium and application which are used for optimizing the pile penetration depth and consider the space effect of a narrow foundation pit, wherein the method is simple in calculation and high in reliability. The aim of the invention can be achieved by the following technical scheme: a method for calculating the passive soil pressure of a limited soil body in consideration of the space effect of a narrow foundation pit comprises the following steps: Acquiring a narrow foundation pit calculation parameter, and determining a space effect increase coefficient according to the narrow foundation pit calculation parameter; calculating and obtaining the soil passive soil pressure intensity based on the space effect increase coefficient and an improved Rankine method, so as to obtain the soil passive soil