隧道施工诱发地表沉降估算方法及其规律分析

通过搜集大量文献，系统地总结了地表沉降槽特性参数的取值方法，并以中国20多个城市的地铁工程地表沉降实测资料为背景，基于Peck公式反演分析法，获取了隧道在不同相对埋深 、不同地层条件和不同施工方法下的地表最大沉降量 、沉降槽宽度k、地层损失率 等参数的变化规律。研究结果表明，（1）采用Peck法估算地表沉降需要基于大量实测资料和结合地域特性和具体施工方法才能得到比较合理的预测结果，不同地区地铁隧道的相对埋深 为0.55～4.43，其地表最大沉降量 为 1.5～ 146.0 mm，沉降槽宽度系数 为0.13～1.60，地层损失率 为0.06%～6.90%，其中 和k与 呈反相关， 受施工工艺和地层条件影响较大；（2）砂性土地层中浅埋暗挖法及其辅助工法的灵活性优于盾构法，黏性土及其互层地层中的盾构法施工在控制地层损失上较浅埋暗挖法要好。

Estimation method and laws analysis of surface settlement due to tunneling

Surface settlement estimating methods are summarized on the basis of Peck method and measurements, and discussed by collecting large amounts of references data. The surface settlement characteristic parameters of more than 20 cities are back analyzed by using Peck method. The variation regularities of maximal surface settlement , settlement trough width ratio k and volume loss are obtained. The results show that: (1) Geographic variations and detailed construction technologies shall be deeply taken into account by using Peck method based on the measurements. The statistical results show that the relative buried depth of tunnel is 0.55-4.09; is -1.5 to -146.0 mm; k is 0.13-1.60; is 0.06%-6.90%, among them and k are negatively correlated to ; and has a significant relationship with the construction technologies and stratigraphic conditions. (2) For effectively controlling the ground movements, shallow tunneling method and assisting construction method are more flexible than the shield tunneling method in the sandy strata; on the contrary, the latter is superior to the former in the clayey soil for reducing the volume loss.