Stress Analysis of Waterproof Single-layer Lining Composite Structure in Metro Tunnels Based on Intermediate Layer Theory
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 8
Abstract
Objective The application of sprayed waterproof membranes can enable composite action between the shotcrete and the waterproof membrane in metro tunnel linings. However, there is currently no design guidance or reference literature for analyzing waterproof single-layer lining composite structures. A design method is proposed to determine the thickness of the tunnel single-layer lining composite structure and to allocate bending moments according to stiffness based on intermediate layer theory. Method The theoretical derivation of equivalent thickness and bending moment distribution is first conducted. The Qingdao Metro Line 1 Xizhen Station is selected for calculating the equivalent thickness and bending moment distribution of each layer, yielding theoretical analytical solutions. To verify the accuracy of the theory, numerical simulation analysis is performed using the finite element Ansys, comparing and discussing the equivalent thickness and bending moment distribution for different second layer shotcrete thicknesses in tunnels. Finally, indoor experiments are conducted to perform four-point beam tests comparing structures with and without a sprayed waterproof membrane. The equivalent thickness of the composite structure is calculated through the reverse deduction of the bending strength reduction ratio of the intermediate layer structure. Result & Conclusion The proposed design method can accurately determine the equivalent thickness and bending moment distribution, proving to be both reasonable and feasible.
Authors and Affiliations
Shuyi WEN, Yisan DENG
Calculation Method of Crowd Density in the Local Area of Subway Station Platform
[Objective] The calculation method of crowd density is the key to analyzing the risk of crowd gathering on subway station platforms. Usually, the internal density distribution is uneven when it is crowded, and there ar...
Energy Consumption Analysis and Verification of Permanent Magnet Direct Drive Metro Trains
Objective The permanent magnet direct drive technology for metro trains, as a novel traction solution, offers certain advantages in energy saving and noise reduction. Thus, it is aimed to specifically investigate its ene...
Electromagnetic Field Analysis of Dual-power Traction Power Supply System in Rail Transit Depot under AC-DC Switching Power Supply Mode
Objective The AC-DC (alternating current-direct current) dual-power traction power supply system depot features densely distributed tracks and relatively close catenary clearance. Different power supply modes can affect...
Prediction of Excavation Disturbance and Required Support Force for Tunnel beneath Existing Structural Foundations
[Objective] It is inevitable that construction of new tunnels or other underground engineering projects will pass through some building structures, causing disturbances to the existing structural foundations. Therefore,...
Research and Engineering Application of Key Waterproof Technology for Underground Stations with Assembled Superposed Structure
[Objective] Underground stations constructed in soil and rock layers are subject to long-term groundwater erosion and pressure infiltration. If waterproofing measures fail, water leakage issues may arise. Such leakage...