泥水加圧式推進工法における推進力の評価

Abstract

Recently, for the concern of safety in construction as well as for environmental and economical reasons, an efficient small-diameter shallow tunneling method has become increasingly important for outside plant engineering such as water supply, gas, electricity and telecommunications. In particular, for construction work near existing facilities, an underground tunnel excavated by the pipe jacking is becoming increasingly popular to avoid adverse effects. Basically, the pipe jacking system involving the pushing or thrusting of the drivage machine through concrete pipes ahead of jacks. The method utilizes the mud slurry which is formed around the pipes for stability of surrounding soil. The Japan Sewage Association proposed empirical prediction equations of the thrusts in using the pipe jacking method. However, these prediction equations are not accurate. From this point of view, the major purpose of this study is to find the way to predict the thrusts in using pipe jacking. In pipe jacking, the performance of the mud slurry plays an important role in the pushing process. The thrusts in pipe jacking can be predicted well by using the initial thrusts and the resistance between the mud slurry and concrete pipes.