隧道施工引起建筑物变形预测的刚度修正法
Modified stiffness approach to predict deformation of building induced by tunnelling
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摘要: 城市深基坑开挖或地铁隧道掘进会引起附近建筑物或其他结构的变形。长期以来对由于地层位移引起的建筑物变形的预测方法的研究还比较少,由于考虑结构刚度作用的复杂性,除了数值分析方法以外,一般在工程实践中均忽略了结构刚度对其变形的影响作用,因此结构变形预测结果大大偏于保守。在理论分析的基础上,通过机理研究和实测数据的分析,提出了体型简单、结构刚度均一的多层建筑物沉降的高斯分布模型与结构刚度影响机理;基于实测资料给出了系数K和结构剪切刚度经验关系,建立了一个考虑建筑物结构刚度的建筑物沉降曲线的预测方法–刚度修正法,是基本反映了隧道–土–结构相互作用效果的一种工程实用方法。通过北京地区的工程实测资料验证了本方法的有效性。Abstract: The urban tunnel construction will cause ground movement and the deformation or even damage of the nearby buildings or other structures. It’s very common in practice that the stiffness of structure may be ignored in the settlement prediction and damage assessment of building because of the nature of the complexity of tunnel-soil-structure interaction. Based on the study of 29 sets of settlement profiles measured from Jubilee Line Extension project, London, an observation is put forward that the settlement profiles of the building also can be fit very well by the Gaussian equation in case of using a larger trough-width parameter K influenced by the structural stiffness. Thus an empirical relationship between the parameter K and the shear stiffness of the building is proposed which can be used to predict the trough parameter according to the building stiffness, and a ‘Modified Stiffness Method’ is suggested. Compared with the numerical approach, the present method is a simple and efficient way that considered the result of the complicated tunnel-soil-structure interaction effects. The effectiveness of this method is evaluated by the monitoring data from Beijing.