Optimized Partition Scheme for Prefabricated Underpass with Large Cross Section

Zhiyi Jin,Xiao Liang,Taiyue Qi,Bo Lei,Guoyang Fu

doi:10.1155/2021/8820287

Zhiyi Jin, Xiao Liang + Show 3 more

Open Access

https://doi.org/10.1155/2021/8820287

Copy DOI

Abstract

With the acceleration of urbanization in China, more underpasses will be constructed in big cities to alleviate the great traffic pressure. The prefabricated and assembly construction method has been introduced to replace the traditional cast-in-place method to achieve quick construction. However, for a fully prefabricated and assembled underground structure (PAUS) with large cross section, the structure must be cut into segments in transverse direction to reduce the size and weight for easy transportation and assembly. Therefore, how to develop an optimal partition scheme is a new problem to be studied. Firstly, three preliminary partition schemes were proposed based on the internal force distribution and completed engineering practices. Then, the three schemes were compared in terms of bending moment, shear force, and axial force. The construction efficiencies were also compared with special emphasis on difference of the build period. Finally, an optimal partition scheme was determined and successfully applied in the real project. Furthermore, the construction period of this partition scheme was 1/3 of the traditional cast-in-place method. The results of the current paper can provide some design guidance to large cross-sectional underpasses and other underground structures in the partition stage.

Highlights

With the fast development of urbanization in China, traffic congestion has become an urgent problem in big cities
The construction of most underpasses is based mainly on traditional cast-inplace concrete technology, which has both adverse environmental and social adverse effects, such as long construction time, large construction space, and environmental pollution. us, due to the improvements in building technology, the increasing public awareness of the importance of protecting the environment, and the need for construction to take place quickly, the national and local governments have issued policies that vigorously promote the use of prefabricated buildings. erefore, in the coming decades, the traditional cast-in-place structures will be replaced by prefabricated assembly structures (PAS)
Casteren studied the feasibility of placing prefabricated and assembled underpass (PAU) under the railway, and it was concluded that PAUs were both technically and economically feasible [1]

Summary

Introduction

With the fast development of urbanization in China, traffic congestion has become an urgent problem in big cities. For circular shape shield tunnels with diameter between 8 and 15 m, the number of segments is from 8 to 10 These studies of partition schemes of lining segments mainly concentrated on shield tunnels which consider the limitation of the assembly space due to the construction method. In recent years, prefabricated subway stations have appeared in China, and many literatures focused on the performance of the station under seismic loads by model tests and numerical simulation These studies rarely considered the partition schemes which are significant to the transportation, assembly, and joints performance [16,17,18,19]. E maximum allowable height and axle of the transport rout had to be determined prior to designing the partition scheme. e height limit and the maximum allowable axle weight of the road, which the transportation of segments passed, are 5 m and 20 t, respectively

Jinjiang district e precast underpass Jinjiang river

Unit Segments

Number of joints