沈阳地区大直径顶管顶力预估与减阻效果的数值模拟

沈阳地区以砂卵(砾)石土层为主，顶进大直径顶管可借鉴的工程经验不多，因此首先从数值模拟的角度，提出了根据初始顶力预估顶进过程中所需顶力的方法，并与实际监测结果进行了对比，然后对沈阳地区顶管顶进中使用的触变泥浆配合比进行了分析，比较了7种浆体的顶力曲线.研究结果表明:采用数值模拟方法预估顶管顶进过程中的顶力，并为中继间的合理布置提供参考是可行的；在沈阳地区顶管施工中优化的触变泥浆膨润土与水的质量配比为1∶9，并且触变泥浆中的用水量对于减阻效果有明显影响.

Numerical Estimation on Jacking Force and Resistance Relieving Effect of Large-Diameter Pipe Jacking in Shenyang

The experience of pipe jacking in sand and gravel conditions in Shenyang is limited， especially for pipes with large diameter.So， a numerical method of forecasting the jacking force during construction was put forward based on the initial jacking force， and then jacking forces calculated from numerical simulation were compared with in situ monitored values. Finally， the effect of resistance relieving by using different proportion of thixotropic fluids was numerically analyzed and the jacking forces of seven fluids were contrasted. Simulation results indicate that the numerical method used in this work is feasible in forecasting the jacking force， thus being helpful in reasonably arranging the intermediate jacking stations. It is also shown that the water content in thixotropic fluids has significance influence on the resistance relieving effect of pipe jacking and the optimized proportion of bentonite and water is 1∶9.