Analysis of Ground Movements and Segment Stress Induced by Shield-Tunneling in Sandy Soil at Kaohsiung

• Main Authors: Chao-Chun Kuo, 郭昭君
• Other Authors: Bin-Chen Benson Hsiung
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/27232752194759094575

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 99 === Due to limited space of surface level in urban area, many underground works of public infrastructure are undertaken by shield- machine bored tunnel instead of cut-and-cover one. Several characteristics which shield- machine bored tunnel has include limited interruption to the environment on surface, smaller space used for construction, not affected by the weather and it can be possibly operated 24- hour a day. However, boring of the tunnel may induce additional deformation and such deformation may be connected with damage of adjacent structures. It is thus essential to explore how to minimize such displacements as well as to prevent the hazard related to ground deformation. Two main research schemes in this study are (1) to deliver works by the use of numerical simulation and centrifuge test to evaluate displacements caused by the construction of tunnel and then evaluate possible influences on piles near the tunnel; (2) to examine the stresses of tunnel segments based on application of numerical analyses, conventional design method and beam- spring method. The results of this study show that the surface settlement measured at central axis of tunnel from centrifuge test is greater than the one from observations and results of 2- dimensional and 3- dimensional analyses. In addition, considering the results of numerical analyses, it was recommended that a larger volume loss rate leads to larger stresses of the pile. The results of centrifuge test present that the pile cap has the maximum axial force and bending moment rather than anywhere else. At last, for analyzing stresses of tunnel segments, it was found that the one using the conventional design method is the maximum.