Case Study of The Effect of Cement Jet Grouting on the Outward Displacement of Diaphragm Wall

• Main Authors: Daw-Liang Kan, 甘道良
• Other Authors: Tta-Teh Chang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/40483822211064798031

碩士 === 中原大學 === 土木工程研究所 === 94 === ABSTRACT Key words： Chemical Churning Pile、soft ground、diaphragm wall displacement Chemical Churning Pile is often used in deep excavation projects on soft ground. The purpose is to modify the geotechnical properties, to increases the strength of soil and passive soil pressure in the district, and to improve the liquefaction resistance of in-situ soil. It not only increases the stability of excavation, but also limits the lateral displacement of retaining walls. The case of this paper applies the expansive model of Chemical Churning Pile to modify soil properties directly inside the pile, and indirectly by permeating the soil mass outside the pile. It not only modifies the liquefaction resistant potential and limits the amount of diaphragm wall displacement effectively, but also increases the bearing force and the shear resistance of soil. However, it is frequently found that may induce the lateral outward displacement of diaphragm walls and the heave of the surrounding ground. Its displacement degree may exceed 10 cm, even cause the wall body to crack and seriously affect the project quality and security. Consider a great deal of documents and record, the outward movement of diaphragm walls is not induced by the seemingly high grouting pressure in fact, difficulties in expelling waste disposal from the grout hole or disturbing the soft surrounding ground excessively that leads to expansion of the soil mass is perhaps the governing mechanism. It causes the wall body to crack and the surrounding ground to shift excessively. So the supervision of constructional quality and procedure, and the choice of construction machinery are of utmost importance. The project case of this paper is near the Tamsui Line of Taipei Rapid Transit System. The demand of quality and the consideration of security are especially very rigorous. By the monitoring result and the effect of improving on the case, shows the case of a construction with good quality. So the author of this paper makes great efforts in many aspects to collect the materials and gather together whole to this project case, consult the domestic and the foreign papers and a great deal of experiences of project case. The mechanism that leads to the outward movements of diaphragm wall is also delineated via a theoretical approach. Analysis, assess and propose, and offer to the advanced persons of geotechnical engineering be the reference for the similar project case.