盾构始发采用化学加固方式时的设计方法及加固工艺

盾构始发是盾构隧道施工中的事故多发阶段,如何保证该阶段加固土体的强度和安全性,从而确定土体加固的范围,是盾构隧道施工中必须解决的问题。文章介绍盾构隧道端头常用的土体加固方式以及目前盾构始发设计施工中所采用的计算理论及模型,结合苏州地铁滨河路站西端头盾构始发工程进行理论设计与验算,并且讨论软土地区常用加固方式的加固时机、加固所采用的技术参数以及应急措施。研究得出：对于软土地区,采用最多的是水泥土深层搅拌桩＋高压旋喷桩（或注浆）的加固方式;抗滑移验算对安全系数起主导因素的是加固土体的粘聚力;土体扰动极限平衡理论计算得出的横向加固尺寸小于构造要求,只要能够满足构造要求,土体在抵抗扰动上就有足够的安全系数。

Design Method and Reinforcement Technology of Shield Launching Using Chemical Strengthening Methods

Shield machine launching is an accident-prone stage in shield tunnel construction and the problem must be solved in construction is how to ensure the safety and strength of the reinforced soil in order to determine the scope of soil reinforcement.The commonly used method of soil reinforcement in shield tunnel end was introduced,as well as the applied computational theory and models in current design and construction of shield machine launching.Combined with the shield machine launching engineering in BinHe Road subway station＇s western end in Suzhou,its theoretical design and checking calculation was conducted.Meanwhile,the reinforcement time,technical parameters and emergency measures of commom reinforcement methods used in soft soil area were discussed.It was concluded that in soft soil area,the reinforcement method which combined deep soil cement mixing pile and high-pressure jet grouting pile（or grouting） was most widely used and the dominant factor effecting safety coefficients was the cohesive strength of reinforced soil through anti-sliding checking.The transverse reinforcement size calculated with the limit equilibrium theory of soil disturbance was less than construction requirements,and as long as it could satisfy the structural requirements,the soil would have enough safety coefficients in resisting disturbance.