Research Strategies on New Prefabricated Technology for Underground Metro Stations

Self Cite

The grouted mortise-tenon joint, invented as the connection between the large prefabricated elements, is the most important component in the prefabricated underground structures. This paper conducts analysis of load-carrying capacity performance and failure mode with 1 : 1 prototype test in key working direction of different double mortise-tenon joint types for the prefabricated metro station. The resistance moment is developed and used to analyze the bending bearing characteristic curve, and the corresponding test results of each stage of the characteristic curve are described in detail. In addition, the bending bearing performance of different types of double-tenon joints under different load conditions is compared. The test results clarify the ultimate failure mode of double-tenon joint and the variable bearing capacity characteristics of the joint with the increase in axial load and explain the bearing performance of each stage. It is also found the auxiliary pretightening device is helpful to delay the appearance of cracks and improve the bearing capacity, especially when it is set on the tension side. The research results have important application value for the joint design of prefabricated metro station structures.

Section: Introductionmentioning

confidence: 99%

Experimental Research on Bending Bearing Capability of Grouted Double Mortise-Tenon Joint for Prefabricated Metro Station Structure

Yang

Fang

Huang

2021

Self Cite

“…Prefabricated and assembly technology has a long history in the construction of underground structures, and it has been used in many practical projects in some developed countries, such as Japan, Tashkent subway Soviet Union, Netherlands, and France [2][3][4][5][6]. In recent years, with the advancements of both machinery and building technology, several PAUs have been built successfully in China, for example, the Shugang road municipal underpass beneath Xianyue road and a prefabricated utility tunnel [7].…”

Section: Introductionmentioning

confidence: 99%

Optimized Partition Scheme for Prefabricated Underpass with Large Cross Section

Jin

Liang

et al. 2021

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.

“…To address these problems in cold regions, Yuanjiadian station on Line 2 of the Changchun Metro (shown in Figure 1) was selected in 2012 as a test section to conduct research on applications of prefabricated technology in underground engineering. To date, five prefabricated metro stations have been completed, and remarkable results have been achieved [1]. Using prefabricated structures, site assembly and construction can be conducted without the need for wet spraying of concrete and can accordingly reduce environmental pollution and resource consumption as well as address many construction problems faced during the winter in cold regions.…”

Section: Introductionmentioning

confidence: 99%

Influence of Geometrical Parameters on Performance of Grouted Mortise and Tenon Joints for Application in Prefabricated Underground Structures

Yang

Shi

Fang

2019

Self Cite

Prefabricated underground structures were first researched in China to address the serious social and environmental issues associated with underground construction. Five metro stations have been built on Line 2 of the Changchun Metro in China using this new prefabrication technology. The joints connecting prefabricated elements are the most critical components in such prefabricated structures. In this study, experiments and numerical simulations investigating the influences of different grouted mortise and tenon joint geometrical parameters were conducted to determine the optimal parameters and ensure proper performance. To do so, a finite element model was built with the appropriate characteristics using the experimental results, and an analysis of the influence of different geometrical parameters was conducted. The results indicate that increasing the dip angle of the tenon could improve the flexural rigidity of the joint, but its effect was relatively small compared to that of the other parameters. Increasing the width of the tenon only had a positive effect on the flexural rigidity of the joint when the width was relatively small and under small axial loads. Increasing the length of the tenon helped to enhance the flexural performance of the joint; however, this advantage was not obvious when the tenon length was relatively long. Proper indentation of the joint improved the flexural capacity under a small axial load, but was not beneficial under a high axial load. The findings of this study are of value to help researchers and engineers more effectively design prefabricated underground structures.