Efficiency of Buttress Walls and Cross Walls for different Excavation Area in Deep Excavation

• Main Authors: Zong-Yi Lin, 林宗毅
• Other Authors: Shui Loong Chen
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/dv8829

碩士 === 國立臺北科技大學 === 土木與防災研究所 === 101 === Ground improvement is introduced in many deep excavations in Taiwan for the improvement of soil stiffness and strength. Buttresses and cross walls are brought in to replace ground improvement in Taiwan in recent years. However, the lack of standard design specifications for buttresses and cross walls in Taiwan forces geotechnical engineers to design them based on experience and numeric analysis results. Plaxis 3D, a 3D numeric analysis program developed based on the “finite element method,” was used to explore the efficiency of buttresses and cross walls. The data gathered from real-life cases were used to verify whether the results of buttresses and cross walls from program simulation were consistent with the monitoring data. The length and width of engineering cases were scaled down to determine the behaviors of buttresses and cross walls with different intervals. The analysis showed that the buttresses and cross walls were effective in reducing the lateral displacement in diaphragm walls and the influence range of settlement troughs. The cross walls performed better than buttresses. A certain relation was observed between the changes in the interval between walls and the displacement reduced. A linear equation was derived from the analysis results. The linear relation between the DRR value of diaphragm walls and the interval between cross walls was y= -30.855x+93.802; that between the DRR value of diaphragm walls and the interval between buttresses was y= -30.725x+67.065; that between the SRR value of diaphragm walls and the interval between cross walls was y= -21.251x+97.807; and that between the SRR value of diaphragm walls and the interval between buttresses was y= -32.027x+75.364. The results will contribute to the design of buttresses and cross walls used in deep excavations.