弹性位移反分析对地应力、弹模的反演唯一性

Inversion uniqueness of elastic displacement back-analysis for ground stress,elastic modulus and Poisson's ratio

地下工程中的平面线弹性问题共有 5个被关心的参数 ,即竖直、水平及剪切地应力分量、弹模和泊松比。利用单个洞室存在时的位移解析解对位移反分析所能辨识出的参数个数作了进一步的研究 ,发现所有地应力分量和弹模同为未知量时的反演不具有唯一性 ;此外 ,无论洞室形状如何 ,都有可能唯一地反演出各种组合下的未知参数 ,但形状简单的洞室对参数的限制条件较多。

Vertical,horizontal and shear components of ground stress,elastic modulus and Poisson's ratio are five important parameters for plane problems of underground engineering.The present paper makes further investigations about the number of the parameters that are possibly identified by the elastic back-analysis from displacements,using the analytic displacement solution of a single tunnel.It is found that the inversion isn't unique when all ground stress components and elastic modulus are unknown parameters to be back-analyzed.Besides this case,all the unknown parameters are possibly inverted only that the inversion for tunnel with simple geometry places more limits on the parameters to be identified.