The effect of the additional load on the ground support on the settlement of the surrounding ground

Dong Wang,Zhengyue Shi,Wenkai Zhang,Hongxu Song,Zhongjing Hu,Xu Zhang,Junpeng Liu,R Ruan

doi:10.1051/e3sconf/202127202015

Dong Wang, Zhengyue Shi + Show 6 more

Open Access

https://doi.org/10.1051/e3sconf/202127202015

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Abstract

Based on the existing engineering examples, this paper uses numerical simulation combined with the actual monitoring values on site to study the effect of the additional load on the support and the settlement of the surrounding ground, and the following conclusions are drawn: (1) When the enclosure structure is good, the settlement curve generally assumes a “spoon shape”. As the distance from the foundation pit increases, the surface settlement curve first increases and then decreases. The distance between the location of the maximum surface settlement and the foundation pit is generally half of the maximum excavation depth of the foundation pit. (2) The existence of additional load accelerates the rate of change of surface settlement, making the soil settlement from the excavation of the first layer of soil as a whole smaller than the unacted additional load to the excavation to the bottom layer as a whole larger than the unapplied load. (3) There will be a certain gap between the numerical simulation and the actual monitoring value. This gap will become larger and larger as the excavation of the foundation pit continues, but the law of change between the two is the same.

Highlights

At this stage, due to the prosperous commerce and dense population in the city center, the land use is constantly in short supply
(2) The existence of additional load accelerates the rate of change of surface settlement, making the soil settlement from the excavation of the first layer of soil as a whole smaller than the unacted additional load to the excavation to the bottom layer as a whole larger than the unapplied load
(3) There will be a certain gap between the numerical simulation and the actual monitoring value

Summary

Introduction

Due to the prosperous commerce and dense population in the city center, the land use is constantly in short supply. Most of the deep foundation pits and ultra-deep foundation pits are located in the prosperous areas of the city, and are often close to various buildings and underground pipe corridors, resulting in small construction operations At this time, there may be a certain amount of piled load around the foundation pit, and even this piled load will act on the support, which will cause a certain disturbance to the surrounding soil, which will cause a certain risk. Numerical simulation is an important method to study the mechanical characteristics of the deep foundation pit construction process. Referring to Peck and Schmidts theory, Xueyuan Hou (Tong ji University, Shanghai, China) developed the formation loss method deriving from the triangular settlement formula to estimate the ground tunnel settlement of shield tunnels. The support system of deep foundation pits with such phenomena is optimized

Site characteristics

Model building

Findings

On-site monitoring