Mechanism and stability analysis of trench wall instability in extra-deep irregular-shaped diaphragm wall trenching construction
Year: 2025
Type: article
Abstract: The instability of extra-deep irregular diaphragm wall trenches, particularly in L-shaped configurations,presents significant challenges in geotechnical engineering. This study develops a 3D failure model using limit equilibrium theory to address these challenges, incorporating the coupled effects of groundwater depth, slurry pressure,heterogeneous soil layers and surficial overload. A safety factor formula for L-shaped trench walls is derived, providing a quantitative framework for evaluating trench stability. The study uses an ultra-deep foundation pit station on the Guangzhou Nansha Zhuhai Intercity Railway as a case study, where finite element simulations are conducted to calculate displacement responses and safety factors. The simulated safety factors are in high agreement with theoretical calculations, with discrepancies of less than 10 percent, validating the proposed model. The findings show that wall reinforcement significantly reduces lateral displacement, with unreinforced trenches experiencing up to 168.5 mm of inward displacement, which drops to 67 mm with reinforcement. Additionally, controlling slurry specific gravity within optimal、ranges of 1.25 g/cm3 to 1.30 g/cm3 for the silt layer and 1.15 g/cm3 to 1.20 g/cm3 for the silty clay layer proves crucial in managing trench stability. This work provides a robust theoretical foundation for designing extra-deep irregular diaphragm walls under complex geological conditions.
Source: Results in Engineering
Authors: Yan-kai Wu, Run-min Hao, Ya-nan Peng, Yuan-zhi Tan, Hui Li, Chang-hui Gao
Language: English
Subfield: Safety, Risk, Reliability and Quality
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
Awards: G1113215972, G6189362644
OpenAlex ID: W7107871028