盾构机始发与到达端头土体加固分析

研究目的:盾构法隧道施工中,端头土体加固是盾构机始发、到达技术的一个重要组成部分,也是盾构机始发、到达事故多发地带,即端头土体加固的成功与否直接关系到盾构机能否安全始发、到达。因此,合理选择端头加固施工工法和必要的加固监测,是保证盾构法隧道顺利施工的非常重要的环节。研究方法:作者依靠多年的工程实践,主要分析了端头土体加固的目的、加固范围和土体加固的施工方法及其适用性,最后对端头土体加固的质量影响因素和加固效果检测进行了分析总结。研究结果和结论:端头土体加固与一般地基加固的不同之处是不仅仅要有强度要求,还要有抗渗透性要求。在此基础上,还要考虑经济的要求,这主要由加固长度、宽度、加固方法的选择决定的,即加固方法是否存在风险性过大,或过于保守,加固范围过大等。目前大多数的承包商往往在端头加固的一项的报价较低,如何采取经济合理、安全可靠的加固方法,是我们共同面对的一个课题。

ANALYSIS OF SOIL REINFORCEMENT FOR THE STARTING AND ARRIVING OF SHIELD MACHINE IN METRO CONSTRUCTION

Research purpose: In the shield tunnel construction, the starting and arriving of shield machine's technology is an important section. Whether the soil improvement is available or not have an impact on the safety of the shield machine's starting and arriving. So, reasonable construction methods for improved soil and necessary supervising measures guarantee the construction of shield tunnel. Research method: Based on the authors' long time construction experiences, this paper analyzed the effects of soil improvement, scope of the soil improvement and application of construction for soil improvement. Finally, this paper summed up the accidents caused by worse soil improvement and the supervising method for soil improvement. Research result: This research shows that the differences between soil improvement of end tunnel and general soil improvement are not only in strength demand and also in anti-seepage demand. For soil improvement of end of tunnel, economy is meeded to be considered, which is determined by length, width, methods of soil consolidation. That is to say that soil improvement deals with whether the risk and width of soil improvement are more. Research conclusion: At present, the majority contractor often give lower quoted price for the end reinforcement, so we must face the problem that how to take economic, reasonable and safe reinforcement measures.