富水强渗透圆砾地层土压平衡盾构掘进参数分析预测

Parameter Analysis and Prediction of EPB Shield Tunneling in Highly Permeable and Water Rich Gravel Stratum

盾构法已广泛应用于地铁建设中,砂卵石、软土等地层的盾构施工技术日趋成熟,而强渗透富水圆砾地层中土压平衡盾构施工仍存在掘进参数合理设定等技术问题。本文依托呼和浩特轨道交通2号线帅家营-内大南校区的区间隧道工程,采用统计学方法对各掘进参数分布范围进行研究,得出强渗透富水圆砾地层土压平衡盾构合理的掘进参数范围,并通过分析地表变形监测数据对掘进参数合理性进行验证;对各掘进参数相关性进行探讨,并以此建立基于BP神经网络的推进速度预测模型,经检验后本模型的预测值与实测值变化趋势几乎一致,平均预测误差约为5%.本文所确定的掘进参数合理设定区间及预测模型可为类似工程提供参考。

Shield method has been widely used in subway construction,and the shield construction technology becomes increasing mature in the sandy gravel and soft soil stratum,but there are still some technical problems related to the reasonable setting of tunneling parameters in the earth pressure balance shield construction in the strong permeable and water rich gravel stratum.Based on the tunnel engineering of Shuaijiaying-Neidanan of Huhhot Rail Transit Line 2,this paper studies the distribution range of excavation parameters by using statistical method,and obtains the reasonable excavation parameters range of EPB shield in the strong permeable and water rich pebble stratum,and verifies the rationality of excavation parameters by analyzing the surface deformation monitoring data.In addition,it discusses the correlation of various excavation parameters,and the prediction model based on BP neural network is established.After testing,the prediction value of the model is almost the same as the measured value,and the average prediction error is about 5%.The reasonable setting interval and prediction model of driving parameters determined in this paper can provide some reference for similar projects.