基于排土量与注浆量的盾构施工地表沉降预测

Surface settlement prediction caused by shield tunneling based on soil discharge quantity and grouting volume

盾构法已成为隧道施工最主要的方法.通常盾构租赁方和施工方是各自独立的,该方法的提出可以使盾构租赁方仅凭盾构机本身而不依赖于施工方的测量数据便可知悉地表沉降情况,从而掌握施工状况.对Peck公式进一步推导,实现仅根据盾构施工的排土量与注浆量数据就能对地表沉降值进行预测.提出了利用电子皮带秤动态测量输送机上散料质量,通过积分法切片累加的排土量测量方法,以及通过拉绳位移传感器和压力传感器甄别注浆有效性的注浆量测量方法,实现通过盾构机有效获取排土量与注浆量数据.在上海某区间的实际运行测量试验,验证了利用排土量与注浆量预测施工隧道最大地表沉降值的方法是行之有效的.

Shield method construction has been the major method in tunnel construction.Usually the leasor of shield machine and the construction company are independent to each other.The aim of the method proposed is to let the leasor pick up the situation which can be used to calculate the surface settlement without measured data provided by the construction company.First taking further derivation of Peck formula as the theoretical basis,settlement prediction can be down based on soil discharge quantity and grouting volume which can be acquired by shield machine itself instead of field measurement.Then the way to gain soil discharge quantity and grouting volume are proposed.Weight of soil is measured dynamically by electronic belt scale and then used to calculate soil discharge quantity by integration method.Grouting volume is calculated by the data measured by draw-wire displacement sensor and pressure sensor which can tell whether the grouting is valid by comparing pressure value with effective pressure threshold.Finally an example of surface settlement prediction of shield tunneling in Shanghai is given to show the feasibility and effectiveness of the proposed method.