基于区域地质信息的盾构掘进参数自适应调整及地面沉降控制方法

Self-adaptive Adjustment of Shield Tunneling Parameters and Land Subsidence Control Based on Regional Geological Information

[目的]目前将机器学习方法用于地面沉降预测已经成为一种趋势。然而大多数基于地质参数及盾构掘进参数等构建的地面沉降预测模型方法单一,并且不能够用于地面沉降的实际控制。对此,提出了一种基于区域地质信息驱动的盾构掘进参数自适应调整与地面沉降控制方法。[方法]以南京地铁9号线为例,详细阐述了该控制方法的构建及实施过程。该控制方法采用基于多种机器学习方法的融合算法,分两个阶段。阶段1为模型构建阶段:地面沉降预测模型对施工数据库总体样本进行训练,通过融合算法得到模型A的最优算法;然后,构建模型B(盾构掘进参数优化模型)以地面沉降作为控制指标筛选优质施工数据,训练并通过融合算法得到模型B的最优算法。阶段2为施工阶段,将未开挖或者沉降可能较大的区间相关参数输入到采用最优算法的模型B中,输出优化的盾构掘进参数,从而实现了盾构掘进参数的实时调整和地面沉降的控制。以南京地铁9号线区间为例,通过仿真计算对该方法的应用效果进行验证。[结果及结论]仿真计算结果与实测值相比,优化后沉降最多减小了21.51 mm,验证了该方法的有效性。

[Objective]At present,it has become a trend that the method of machine learning is used to predict land subsidence.However,most of the land subsidence prediction models established based on geological parameters and shield tunneling parameters are simple in terms of method,and can not be used for the actual control of land subsidence.Therefore,a method of self-adaptive adjustment of shield tunneling parameters and land subsidence control based on the regional geological information is proposed.[Method]Based on Nanjing Metro Line 9,the construction and implementation process of the above-metioned method is described into details.The control method adopts the fusion algorithm based on multiple machine leaning methods and contains two stages.In the first stage of model construction,Model A(land subsidence prediction model)is firstly established to train the overall samples of the construction database,and the optimal algorithm of Model A is obtained by fusion algorithm.Then,Model B(shield tunneling parameter optimization model)is established,and the land subsidence is taken as the control index to screen high quality construction data.The optimal algorithm of Model B is obtained by training and fusion algorithm.In the second stage i.e.construction stage,the relevant parameters of unexcavated sections or sections with large subsidence potential are input into Model B using the optimal algorithm,and the optimized shield tunneling parameters are output,thus realizing the timely adjustment of shield tunneling parameters and the control of land subsidence.The application effect of the above method is verified through simulation calculation based on Nanjing Metro Line 9.[Result&Conclusion]By comparing the simulated results and the measured data,the subsidence is reduced by the maximum of 21.51 mm after optimization,verifying the effectiveness of the method.