基于密封舱压力场梯度的盾构开挖面稳定性判定

Stability judgment of shield excavation face based on earth pressure field gradient in pressure chamber

提出了一种基于密封舱压力场梯度的土压平衡盾构开挖面稳定性的判定方法。利用非均匀B样条最小二乘方法建立了密封舱压力场的分布模型,在此基础上,分析了竖直与水平方向压力梯度的变化,基于密封舱压力场梯度范数给出了开挖面的稳定域及判定方法。对于压力场梯度范数的极值,采用多级动态惩罚函数与粒子群相结合的优化算法对优化函数进行求解。最后,利用现场施工数据进行了仿真研究,对密封舱压力平衡、失衡时的压力场及等压线分布特征进行了分析,并进一步对开挖面的稳定性进行了判断,验证了判定方法的有效性。

A judgment method of the shield excavation face stability was proposed based on the earth pressure field gradient in the pressure chamber.A distribution model of the earth pressure field was established by using the non-uniform B spline least squares method.On this basis,the varied ranges of the vertical and horizontal gradient were analyzed,subsequently.The stable region of excavation face and its judgment method were given based on the norm of earth pressure field gradient.For the norm extremum of the earth pressure field gradient,it was obtained through solving the optimization function by means of the multi-stage dynamic penalty function combined with particle swarm optimization（PSO） algorithm.Finally,the simulation experiment was carried out based on the field data,and the earth pressure field and its isobars distribution for the balance and imbalance earth pressure in chamber were studied,further analyzed the excavation face stability,it demonstrates the effectiveness of the judgment method.