Study on Stress and Deformation Mechanism of Side Pile and Middle Column for PBA Method Metro Station in Loess Area
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 3
Abstract
[Objective] In order to ensure the stability of important vertical load-bearing components in the process of station construction with PBA (pile-beam-arch) method in loess area, it is necessary to study the stress and deformation mechanism of side piles and middle columns during construction, and put forward measures to control the deformation in the most unfavorable stress stage. [Method] With Hejiaying Station of Xi’an Metro Line 2 as the research background, the methods of numerical simulation and field monitoring are used to study the horizontal displacement, internal force of steel bar, horizontal earth pressure and strain of middle column of side piles during construction. [Result & Conclusion] Construction of buckle arch, excavation of station hall layer and platform layer are the three most unfavorable stages for horizontal displacement of side piles. During the critical stages of construction, steel support should be set up inside the structure and the disturbed stratum should be properly reinforced. During construction of pile beam and buckle arch, the main rebar of side pile bears axial pressure, while during construction of residual earthwork in the station, forces borne by the rebar of side pile back on the soil side gradually change from axial pressure to axial tension. With the increase of buried depth of side pile, the growth of axial tension pressure slows down. In the construction of the initial support of the buckle arch, the earth pressure reaches the maximum value of 34.5 kPa at the buried depth of 6.6 m of the side pile. As the aforementioned depth deepens, the growth rate of the pile side pressure is significant. Therefore, the excavation of the inner side of the station is the key stage to control the earth pressure of the side pile at the earth facing side. If necessary, grouting reinforcement of the soil behind the pile is helpful to improve the bearing capacity of the pile foundation. During the construction of the mid-span arch, the strain of the middle column shows a trend of decreasing first and then increasing.
Authors and Affiliations
Xuanrong ZHENG, Hui YANG, Xuexuan SHANG, Shaoxiong WANG, Hanjuan YAO, Qi LEI, Kang YANG
Keywords
Related Articles
- EP ID EP732779
- DOI 10.16037/j.1007-869x.2024.03.005
- Views 36
- Downloads 0
Reactive Power Compensation Scheme for Urban Rail Power Supply System Considering Main Substation Resource Sharing
[Objective] The resource sharing among main substations in urban rail transit power supply system can lead to significant cost savings. In this context, it is essential to investigate reactive power compensation schemes...
Mechanical Behavior of Urban Rail Transit Station Structure Based on Existing Shield Tunnel Interval Underground Excavation Construction
Objective Cancer Hospital Station on Shenzhen Rail Transit Line 14 adopts a scheme of large-diameter (8.5 m) shield tunnel expansion featuring tunnel-first and station-later. During the connection of the main station str...
Overview of Articulated Bogie Light Rail Vehicle Investigation Research
［Objective］ To comprehensively grasp market demands and develop a competitive LRV (light rail vehicle) product, investigation research on articulated bogie LRV is conducted. ［Method］ The basic characteristics of ligh...
Research Progress and Prospects on Pantograph-Catenary Arcing in Urban Rail Transit
［Objective］ Pantograph-catenary (PC) arcing degrades the train current collection quality, causes ablation of pantograph carbon strips and contact wires, and consequently affects safety and stability of train operation...
Analysis and Optimization of Influencing Factors for Turnout Lateral Passing Performance of Rubber-tired Metro
［Objective］ In the turnout section, the wheel-rail relationship of the rubber-tired metro vehicle is relatively special as it is the rubber tire that provides running support and the steel wheel that provides guidance....