基于不同本构模型的深竖井群施工对邻近隧道的影响

Influence of Deep Shaft Group Construction on Adjacent Tunnel Based on Different Constitutive Models

深竖井群作为一项高风险工程,其施工过程不可避免会引起周围地层变形,继而对周围建(构)筑物产生不良影响。因此,针对深竖井群施工对邻近铁路隧道的影响,依托某一待建竖井工程,建立深竖井群-周围地层-邻近铁路隧道的三维一体化数值模型,研究了基于不同本构模型的深竖井群施工作用下铁路隧道周围地层及隧道本身的位移变形规律。结果表明,随着施工的推进,周围地层和隧道表现为先隆起后沉降的规律,而水平变形则逐步增大;由于HSS/HS模型和MC模型在加卸载模量方面的差异,利用不同本构模型的计算结果不尽相同;竖井群施工对地层及隧道的影响排序为竖井Ⅰ>竖井Ⅱ>竖井Ⅲ(竖井Ⅳ);隧道变形最大值出现位置与地层变形最大值位置有所不同,其原因在于铁路隧道与Y轴方向成一定夹角空间分布,这种空间分布位置影响了隧道变形极值分布;利用MC模型计算会高估深竖井施工作用下的邻近铁路隧道水平变形值,但会低估其沉降值。研究结果可为类似工程建设提供参考。

As a high-risk project,the construction of deep shaft group will inevitably cause surrounding stratum deformation,which has a negative impact on the adjacent structures.Therefore,considering the influence of deep shaft group construction on adjacent railway tunnel,this paper relies on a shaft project to be built,and establishes a three-dimensional integrated numerical model of deep shaft group.The stress and deformation of stratum and tunnel induced by deep shaft group construction were studied based on different constitutive models.The results show that with the progress of construction,the surrounding strata and tunnel present uplift firstly and then settlement,while the horizontal deformation increases gradually.Due to the difference of loading and unloading modulus between HSS/HS model and MC model,the calculation results by the different constitutive models are different.The influence of shaft group construction on strata and tunnel is as follows:Shaft I>ShaftⅡ>ShaftⅢ(ShaftⅣ).The location of the maximum deformation of the tunnel is different from that of the stratum,which is due to the spatial distribution of a certain angle between the tunnel and the Y axis and affects the distribution of the extreme deformation of the tunnel.Using MC model,the horizontal deformation of the adjacent tunnel caused by deep shaft construction will be overestimated while its settlement will be underestimated.This study can provide useful reference for the construction of similar projects.