基于软土地区隧道不同埋深的Peck公式改进

IMPROVEMENT OF PECK FORMULA BASED ON DIFFERENT BURIED DEPTHS OF TUNNELS IN SOFT SOIL AREA

软土地区中隧道开挖往往面临着较大的风险,Peck公式是目前预测隧道沉降应用最简便也是最广泛的方法,但由于Peck公式直接预测往往误差较大,应结合实际的工程条件采取相应的工程参数。通过对紫之隧道实测数据研究分析,引入最大沉降量的修正系数和地表沉降槽宽度的修正系数,采用线性回归分析的方法,提出了软土地区随隧道埋深变化的地表沉降Peck修正公式,通过实测地表沉降数据得到了最大地表沉降量的修正系数α随隧道埋深z的增大而增大;沉降槽宽度的修正系数β随着隧道埋深的增大而减小,给出了修正系数随深度的拟合公式。修正后的Peck公式能够较好地预测隧道地表的实测沉降数据,且该结论在地质条件相似的其它隧道实测数据中也有较好的验证。

Tunnel excavation in soft soil areas often faces greater risks.The Peck formula is currently the easiest and most widely used method for predicting tunnel settlement.Since the direct prediction of Peck formula often has large errors,parameters of the formula should be modified considering the actual engineering conditions.The correction parameters of the maximum settlement and the correction coefficient of the surface settlement trough width are introduced through the research and analysis of the measured data of the Zizhi Tunnel.The Peck correction formula for the surface settlement of the soft soil area with the depth of the tunnel was proposed by the method of linear regression analysis.Based on the measured surface settlement data,it is obtained that the correction parameter of the maximum surface settlement α increases with the increase of the buried depth z of the tunnel.The correction coefficient of the settlement trough width β decreases with the increase of the buried depth of the tunnel,and the correction parameter is given Deep fitting formula.The revised Peck formula can better predict the measured settlement data of the tunnel surface,and this conclusion is also well verified in the measured data of other tunnels with similar geological conditions.