Analysis of Characteristic of Soil-Cement Mixed Wall and Excavation-Induced Deformation Using PLAXIS

• Main Authors: Bo-Wei Jeng, 鄭柏威
• Other Authors: Horn-Da Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/93290032609262919458

碩士 === 國立臺灣科技大學 === 營建工程系 === 97 === When using the Soil-Cement Mixed Wall (SMW) in deep excavation, the contribution of the soil cement pile is often neglected in the analysis. This study used the Transformed-Section Method to establish a reasonable procedure which can be used to calculate the design parameters of SMW wall considering contribution from the soil cement pile and the steel H-pile. Field cases were used to verify these analytical procedures. The verified analytical procedures were then used to further investigate the effect on the SMW displacement due to the variation of the diameter of soil-cement pile, the H-pile type and the strength of soil-cement pile. This study used a two-dimensional program PLAXIS for the analysis. Elastic-plastic soil model was adopted with a simplified method of considering the small-strain behavior of the adjacent soils. First, a well-instrumented excavation case of top-down method was used to verify the suitability of PLAXIS and the suggested excavation simulation procedure. Then, field cases of SMW were analyzed. Results show that calculated displacements are reasonable and within the range of the measured results. Therefore, the analytical procedure incorporating the Transform-Section Method and PLAXIS seems reasonable for the analysis of excavation behavior supported by SMW. Subsequently, hypothetical cases were used to study the characteristics of the excavation behavior supported by SMW. The difference between the traditional method and the Transform-Section method are about 10.06%~15.98% for wall displacement and 5.72%~16.63% for ground settlement. The results show that increase of the diameter and the strength of the soil-cement pile can reduce the wall displacement by the amount of 5.84%~18.20% and reduce ground settlement 3.36%~13.36%. The results also show that increase of the size of H-pile and soil-cement strength can reduce the wall displacement by the amount of 3.71%~37.97% and reduce ground settlement 2.36%~35.63%. The amount of reduction becomes much less significant when the soil-cement strength exceeds 60kg/cm2. Thus, higher strength of soil-cement greater than 60kg/cm2 is not recommended.