Model Test on Structural Behaviour of Underwater Shield Tunnel with Large Cross-Section Considering Assembling Modes

2011 ◽  
Vol 243-249 ◽  
pp. 3560-3564
Author(s):  
Ji Min Zhou ◽  
Chuan He ◽  
Kun Feng ◽  
Ming Qing Xiao
Keyword(s):  
Cross Section ◽  
Model Test ◽  
Yangtze River ◽  
Water Pressure ◽  
Bending Moment ◽  
Internal Force ◽  
Test System ◽  
Shield Tunnel ◽  
Large Cross Section ◽  
Study Results

Taking Nanjing Yangtze River Shield Tunnel with large cross-section (Φ14.5m) as background, the mechanical characteristic of lining structure under high hydrostatic water pressure for different segmental assembling modes is studied by large-scale similar model test. The test system can control earth pressure, uniform and non-uniform water pressure acting on lining respectively and cooperatively. The study results show that the values and distribution of deformation and internal force vary with different assembling modes. The rigidity of the whole ring for straight joint assembling is less, inducing the deformation larger and internal force smaller, which is unfavorable for waterproofing requirements. The peak positions of bending moment change with the difference of staggered joint assembling modes. Due to the smaller rigidity of K segment, the value of bending moment on that position is less. The most favorable and unfavorable assembling modes are proposed for construction design for Nanjing Yangtze River Shield Tunnel; meanwhile it can also provide important reference to the correlative project.

scholarly journals Optimized Partition Scheme for Prefabricated Underpass with Large Cross Section

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhiyi Jin ◽  
Taiyue Qi ◽  
Xiao Liang ◽  
Bo Lei
Keyword(s):  
Cross Section ◽  
Underground Structure ◽  
Bending Moment ◽  
Internal Force ◽  
Optimal Partition ◽  
Large Cross Section ◽  
Underground Structures ◽  
Cross Sectional ◽  
Partition Scheme ◽  
Urbanization In China

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.

The Study of FEM for Internal Force Analysis of the Sluice Structure

2011 ◽  
Vol 71-78 ◽  
pp. 3275-3279
Author(s):  
Xiao Na Li ◽  
Tong Chun Li ◽  
Yuan Ding
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Internal Force ◽  
Force Balance ◽  
Shearing Force ◽  
Force Analysis ◽  
Reconstruction Project ◽  
Unit Stress ◽  
Reinforcement Design

This paper takes a sluice reconstruction project as an example. The constraint internal force, the related axis force, bending moment, and shearing force at the corresponding section are solved according to the unit stress and internal force balance. Furthermore, technology of mesh auto-generation in cross-section is utilized to plot the internal force graph of the structure directly, which will provide reference for reinforcement design and make it more convenient.

scholarly journals Analysis for bearing performance and construction mechanical behavior of supporting structure for the large cross-section tunnel by half bench CD method

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255511
Author(s):  
Rui Zhao
Keyword(s):  
Cross Section ◽  
Mechanical Characteristics ◽  
Internal Force ◽  
Calculation Model ◽  
Large Cross Section ◽  
Support Structure ◽  
Supporting Structure ◽  
Bending Strain ◽  
Excavation Process ◽  
Deformation Distribution

Based on the engineering practice of large cross-section highway tunnel, this paper reveals the space-time coordinated evolution law of the construction mechanical characteristics and deformation distribution of the support structure in the construction by half bench CD method through field test. At the same time, the mechanical response calculation model of the supporting structure in the partial excavation is constructed, and the mechanical characteristics of the support structure in the partial excavation process are analyzed by above mechanical calculation model. Then, the mechanical and deformation distribution of the feet-reinforcement bolt in the steel frame—foot-reinforcement bolt combined support system is analyzed under different levels of surrounding rock load and different structural parameters of the feet-reinforcement bolt. The research results show that: (1) The internal force of the supporting structure changes most obviously during the excavation of Part Ⅰ, Part Ⅱ and Part Ⅲ, and the internal force of the support structure gradually tends to be stable after a slight increase in the excavation of Part Ⅳ and Part Ⅴ; (2) The horizontal deformation and vertical deformation of the support structure mainly occur in the excavation process of Part Ⅰ, Part Ⅱ and Part Ⅲ, and the excavation of Part Ⅳ and Ⅴ has little effect on the deformation response of the structure. The vertical displacement of the supporting structure is larger than the horizontal displacement, and the dynamic response of the temporary diaphragm structure during tunnel excavation is shrinkage-expansion-shrinkage-expansion; (3) The bending strain of each measuring point decreases with the increase of the distance from the loading point, and the bending strain of section 1 and section 2 is much larger than that of the other three sections; (4) With the increase of the angle, the section position with strain close to 0 gradually moves to the deeper position of the bolt, and the axial strain of each section on the bolt gradually changes from positive strain to negative strain.

Design of Key Process Parameters Test-Bench for 1250mm2 Large Cross-Section Conductor Tension Stringing

2014 ◽  
Vol 1065-1069 ◽  
pp. 2058-2062
Author(s):  
Yong Jun Xia ◽  
Wen Ming Mei ◽  
Chun Hua Hu ◽  
Jin Miao Zhang
Keyword(s):  
Cross Section ◽  
Test Bench ◽  
Test System ◽  
Test Methods ◽  
Test Scheme ◽  
Construction Technology ◽  
Large Cross Section ◽  
Force Analysis ◽  
Limit Test ◽  
Design And Manufacture

This document proposed the test scheme of limit Test-bench structural system under the setting-out conditions of simulating critical state and completed the design and manufacture of the test system through conducting investigation on test methods and equipment of tension stringing construction process, combining the 1,250mm2 large cross-section conductor and construction technology requirements and based on functional positioning, optimization of combined design and force analysis of Test-bench, mechanics analysis of various parts and their connection as well as allowable stress method check. This system was closer to the actual stringing working conditions, and the obtained data were more reasonable and exact and meet the actual engineering demand. In addition, the reliability of this test system has been verified through the test of 1,250mm2 third-class large cross-section conductor.

Study on Selection of Segment Lining Structure for Large Profile Underwater Shield Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1359-1363
Author(s):  
Rui Guo ◽  
Chuan He
Keyword(s):  
Yangtze River ◽  
Shield Tunnel ◽  
Study Results ◽  
Lining Structure ◽  
Selection For ◽  
Joint Form ◽  
Selection Of

Based on Nanjing Yangtze River Tunnel project, the selection of segment lining of large profile underwater shield tunnel was analyzed. Considering from structure force, construction and economic, the comparison and selection for assembling modes, joint form, blocking modes, thickness and width of segment lining was carried out, The better segment lining structure was obtained. The study results can offer references for the design of segment lining of similar large profile underwater shield tunnel.

Study on the Construction Mechanic Behaviors of Different Cross-Section Shape Connected Aisle in the Shield Tunnel with High Hydraulic Pressure

2011 ◽  
Vol 243-249 ◽  
pp. 3472-3475 ◽  
Author(s):  
Shi Min Wang ◽  
Chuan He ◽  
Si Jin Liu ◽  
Lei Lei Lan
Keyword(s):  
Cross Section ◽  
Yangtze River ◽  
Shield Tunnel ◽  
Hydraulic Pressure ◽  
Disaster Prevention ◽  
Obvious Effect ◽  
Section Shape ◽  
Tunnel Section ◽  
Hydraulic Conditions ◽  
Subway Construction

With the construction of large quantities of shield tunnels, based on the consideration of the performance, disaster prevention, relief and tunnel drainage requirement, it becomes more and more important to set the connected aisle in the shield tunnel section. The shape of the connected aisle cross-section has an obvious effect on the deformation and stress of the connected aisle. In order to draw reasonable connected aisle type for the subway construction under high hydraulic conditions, the comparative analysis of stress state of the circular and horseshoe-shaped connected aisle section is applied based on the construction of the connected aisle in the shield tunnel across the Yangtze River in Wuhan subway. It is recommended that the horseshoe-shaped cross-section should be applied to connected aisle construction in the shield tunnel in Wuhan subway.

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