隧道施工引起地层位移预测模型的对比分析

COMPARATIVE ANALYSIS OF STRATA PREDICTION MODELS FOR GROUND MOVEMENT INDUCED BY TUNNEL CONSTRUCTION

在我国城市隧道施工引起的地面变形的研究和工程领域中,随机介质理论法和Peck法是2种应用较广的方法。但是目前对这2种方法各自的应用条件、二者的理论联系、计算结果的关系等方面还没有明确的结论。除此以外,由于随机介质理论法应用经验相对少,相应的关键参数的取值方法也很不成熟,基于理论背景研究和实际算例分析,对随机介质理论法和Peck法进行深入全面的比较和探讨。经过推导认为,Peck法适用于隧道埋深较大、隧道开挖面积较小的情况,是随机介质理论法在隧道埋深较大情况下的一个近似,而不适用于超浅埋的情况。在此基础上,比较二者计算参数的关系,并对随机介质法的2个关键计算参数,即主要影响角和断面收缩半径提出简单而有效的工程确定方法,大大地增强随机介质理论法的工程实用性。通过较多实际工程的验证,证明上述方法的有效性和可靠性。

Stochastic medium method（SMM）and Peck method are widely used in the field of ground movement induced by urban soft ground tunneling in China.However,little is known on their relations of theoretical background,the application conditions,and how to evaluate the results from these two methods.Besides,the determination for the key parameters for SMM is also a problem because of the relative little experience from the engineering application in China.Based on the theoretical background study and case study analysis,the theoretical relationship between SMM and Peck method is discussed;and one of the main conclusions is that Peck method can be regarded as a simplification of SMM,but they both are suitable for relatively deeper excavation condition.However,Peck method is not acceptable for the ultra-shallow tunneling where the specific conditions are expected to cause considerable large errors.Although the Peck method is feasible in most urban tunneling conditions,the SMM has a broader application against Peck method in terms of its theoretical background.The relations between the parameters of these two methods are also studied;and some simple but efficient methods for the determination of the parameters have been proposed.The suggested methods are proven and verified by many practical engineering projects;and they can significantly improve the adaptability of SMM in engineering application.