| In recent years,with the continuous acceleration of urban construction and the continuous improvement of economic level,traffic congestion has become increasingly prominent,and has become an important problem in urban construction.As a sign of green travel,subway has the advantages of environmental protection and high efficiency,which eases the traffic pressure of large cities,and has become one of the commonly used means of transport for citizens.However,with the increase of subway operation time,the continuous change of surrounding environment of subway tunnels and the continuous development and utilization of underground space,the tunnel structure has undergone various degrees of deformation and complicated diseases such as leakage,cracks and void of ballast bed.In order to ensure the stability and safety of the subway shield tunnel structure,it has important engineering guiding significance for the study of deformation and disease causes of shield tunnels in soft soil area,the correlation between tunnel deformation and disease,and the treatment of subway diseases.The main contents of this paper are as follows:(1)By analyzing the engineering characteristics of typical soil layer in soft soil area,this paper summarizes the adverse effects of the construction of subway shield tunnel in soft soil area,and provides a reference for the full study.(2)Based on the data of three-dimensional laser scanning detection,long-term operation monitoring report and tunnel disease database of Metro Line in a soft soil area,this paper makes a comparative analysis of the status of Metro Line,and classifies the serious sections.It is concluded that the deformation of tunnel structure and the causes of the diseases are formed in the two stages before and after operation.The causes of different diseases in the two stages were analyzed in detail,and the causes of different diseases were demonstrated through typical cases.(3)Taking the 4758 rings of segments in 9 protected areas of Line as the research object,through statistical analysis of cracks and other diseases,the correlation between tunnel deformation and diseases is obtained.When the tunnel converges to deformation,the main disease is segment cracks.With the increase of horizontal diameter difference ?D,cracks have an obvious increasing trend.Combining with the corresponding settlement,different preventive and control measures are obtained according to the different deformation degree and disease condition,and the common treatment measures for diseases and deformation are summarized.(4)Combined with two engineering examples,the deformation and disease situation,disease causes,remediation measures and remediation effect of two complex tunnel sections are analyzed.It is verified that the comprehensive remediation measures combined with tunnel leak stoppage,crack repair,micro-disturbance grouting and permanent segment reinforcement are feasible for the remediation of complex disease sections. |
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