Research on Deformation Law of Deep Foundation Pit of Station in Core Region of Saturated Soft Loess Based on Monitoring

Abstract

Saturated soft loess has a large pore structure, high compressibility, low strength, fluid plastic state, and poor engineering properties. It is still one of the key problems that engineering needs to solve. In order to study the influence of deep foundation pit excavation in the saturated soft loess area on the deformation of foundation pits, the deformation laws of ground settlement, enclosure structure, and supporting axial force were clarified based on the field tests on the deformation characteristics of deep foundation pits in areas with the high-water level in saturated soft loess, combined with geological conditions and on-site construction procedures. The results indicate the following: water supply and construction process were found to be the main factor in changing the surface settlement curve of deep foundation pits in saturated soft loess; increasing the construction speed of the pit bottom floor, inverted braces, floor frame beams, and sidewall frame beams to close the structure, which is conducive to restraining the deformation of the continuous underground wall and foundation pits in similar areas. In the initial stage of support layout, the axial force of steel support tends to increase too fast or even exceed the standard control value. Therefore, a reasonable preadding axial force is an effective means to control the deformation of the continuous underground wall and the axial force of the steel support. The current research results may provide a reference for constructing deep foundation pits in similar areas.

Deformation Analysis and Research of Building Envelope by Deep Learning Technology under the Reinforcement of the Diaphragm Wall

“…Through numerical calculation and field measurement, the abnormal change of the seepage field caused by the seepage point was obtained [ 12 ]. Wang et al studied the influence of deep foundation pit excavation on foundation pit deformation in saturated soft loess areas through a field test on deformation characteristics of deep foundation pit in saturated soft loess areas with a high water level and clarified the deformation laws of foundation settlement, envelope structure, and supporting axial force [ 13 ]. DL adopts an unsupervised layer-by-layer training algorithm to realize the effective expression of data feature information and has strong nonlinear data fitting ability.…”

Construction applicability of mechanical methods for connecting aisle in the bohai mudstone stratum with high water pressure

“…established the discrete element model of connecting aisle excavation of the same size, and studied the surface settlement during shield excavation and the particle coordination number in the soil before the excavation. Many other scholars have also done a lot of work in the field of construction technology and risks of connecting aisle (Pei and Tao, 2011;Pei et al, 2013;Han et al, 2015;Li et al, 2015;Li et al, 2019;Wang et al, 2020a;Wang et al, 2020b;Wu et al, 2020;Yuan et al, 2020;Zhang and Zhong, 2020;Yuan et al, 2021a;Yuan et al, 2021b;Dai and Hu, 2021;Du et al, 2021;Ting et al, 2021;Wang and Meng, 2021;Zhang et al, 2021;Yuan et al, 2022a;Yuan et al, 2022b;Yuan et al, 2022c;Kun et al, 2022;Liu et al, 2022;Pei et al, 2022;Wang et al, 2022;Yang et al, 2022).…”

Experimental Study on Shield Tunneling Control in Full Section Water-Rich Sand Layer of Collapsible Loess

“…During the application of EPB shield in water rich sand layer, the determination of shield tunneling parameters is very challenging due to the problems such as low arched efficiency of surrounding rock, high pore pressure, and easy collapse of tunnel working face [1][2][3]. If the construction parameters are set improperly, it is difficult to ensure the safety of the existing structure when the shield machine needs to pass through major risk sources.…”