Risk Analysis And Control Of Astylar Large-Span Mined Metro Station

The construction of astylar large-span mined metro station has the characteristics of long construction period,high strength requirement of surrounding rock,high investment in engineering and large social impact.Qingdao metro line 3 has been built a large number of astylar large-span mined metro stations.In the construction process,there are varying degrees of risk,which effect the construction of Qingdao subway project cost,organization and management,and has other adverse effects.Subway construction accidents cause a huge threat on our people's property and personal safety,especially the collapse is most frequently,and the impact is particularly serious.Therefore,for the astylar large-span mined metro station,which is widely used in the construction of Qingdao subway,it is significant to strengthen the awareness of risk identification at the station,to carry out the risk control measures,to strictly control the settlement and the internal deformation of the tunnel and to monitor it in time.Based on the scientific research project of the China Railway Science and Technology Research Institute,in this paper,the risk analysis and control of the subway station with astylar and large span was analyzed,and the adaptability and risk control of Changle Road Station of Qingdao metro line 4 was studied.Changle Road Station of Qingdao metro line 4 would be designed without column-type large-span structure.In this paper,the adaptability of Changle Road Station was analyzed from the stratigraphic lithology,rock structure,surrounding rock level,groundwater and other environmental conditions.It is concluded that Changle Road Station is suitable for the construction of excavation method,and the risk which may exist in the construction process was identified and assessed,and the concept of engineering risk was introduced.Then,by studying the deformation of surrounding rock caused by different working methods in the construction process,the engineering risk engineering control measures suitable for Changle Road Station were selected.The methods of comparisons were double stacking initial arch cover method and double side wall guide method.The methods of comparison were used to analyze the deformation of surrounding rock by two numerical methods.Through the analysis,it is concluded that the risk control of Changle Road Station is better.Secondly,it is necessary to control the risk in the process of double stacking initial arch cover method.In this paper,the control measures were given for different levels of risk,and the risk control measures of the secondary project were expounded in detail.Finally,through the construction monitoring data analysis,the construction risk control of astylar large-span mined metro station was analyzed.Because the Changle Road Station has not yet been built,the monitoring data of astylar large-span mined metro station-Haichuan Road Station was been used in this paper.The construction method of Haichuan Road Station is double stacking initial arch cover method,and hydrogeological conditions,groundwater conditions are similar to Changle Road Station,so the monitoring data of this station was selected for monitoring and analysis,and the effectiveness of risk control for astylar large-span mined metro station with double stacking initial arch eover method was verified.