桩基施工对邻近运营盾构隧道结构健康趋势影响研究

Influence of Pile Foundation Construction on Health Trend of Adjacent Shield Tunnel Structures

为掌控软土地区深大桥桩施工对近邻运营隧道管片结构健康状态的影响,采用时空分布统计比较和数据联合归因的分析方法进行研究。研究结果表明,管片裂缝主要伴随结构受拉区的产生而发展,主要是腰部纵向裂缝,裂缝条数的数据变异性、离散程度相对裂缝代表宽度要高;邻近隧道的深大基桩施工期间产生挤土效应,控制了管片水平直径差异的发展,近桩隧道管片裂缝增长弱于远桩隧道;裂缝新增条数与桩隧水平距离呈正相关,可据此对管片裂缝条数增量进行估算;水平直径差异可以用来预测和防控管片新增裂缝,严格关注值建议采用20 mm,较大关注值可采用38 mm。

To study the impact of deep bridge pile construction in soft soil areas on the health status of adjacent operating tunnel segments,a spatiotemporal distribution statistical comparison and data joint attribution analysis method were used.Segment cracks mainly arise and develop with the development of structural tension area,mainly longitudinal cracks in the waist,and the data variability and dispersion degree of the number of cracks are higher than the representative width.The extrusion effect of deep and large foundation piles in adjacent tunnels was generated,which controlled the development of the horizontal diameter difference of the segment,and the crack growth of the tunnel segment close to the foundation pile construction was weaker than that of the distant pile tunnel.The number of new cracks was positively nonlinear with the horizontal distance of the pile tunnel,and the increment of the number of cracks in the segment can be estimated.The horizontal diameter difference can be used to predict and prevent new cracks in the segment.The recommended threshold is 20 mm for the first layer and 38 mm for larger values of concern.