Research On The Laws Of Stratumu Loss And Stratumu Settelment Ieduced By Urban Tunnel Construction With Conventional Method And Control Countermeasure

At present, the development and utilization of urban underground engineering are in a high-speed development period in our country with the boost of economic,in the meantime, many geotechnieal problems which need to be solved will also come forth.It may inevitab-ly disturb the underground surface and result in statum settlements and deformations to construct metro tunneling in urban underground space.It will cause damage to surface structures and roads and underground pipelines when soil movemems reach some level.Furthermore,bad social effect and economic loss can be brought out.As a result,it has very important significance to study the laws and reasons and control measures of statum settlements induced by tunneling construction.Based on the study on the vertical displacement of under ground cut tunnel traversing under Railway in the the third phase project of Changchun Light Rail.This article studies the laws and control measures of stratum losses and statum settlements induced by mine tunneling method construction by comprehensive use of the methods such as field survey, numerical analysis,engineering analogy, induction and summarization.1.Study on the formation mechanical response mechanism induced by tunnel construction.make induction and summarization of the laws of stratum deformation induced by tunnel construction.Systemic analysis of stratum loss in the mine tunneling method construction.Summarize the main influencing factors which lead to stratum loss and the action mechanism of them.2.Computational simulation and analysis on the general influence rules to stratum loss and statum settlement by the tunnel depth in the single tunnel constructions or the tunnel depth and the tunnel distance in the twin tunnels constructions separately,and make a research on the displacement ratio induced by any construction step.3.Computational simulation and analysis on the general influence rules to stratum loss and statum settlement by the cavity of different sizes and different ranges behind the initial support in the single tunnel constructions or in the twin tunnels constructions.4.Based on component factors of stratum loss and construction course,put forward corresponding control countermeasures to stratum loss and statum settlement.It mainly includes control countermeasures of stratum losses caused by tunnel excavation, control countermeasures of stratum losses caused by cavity;control countermeasures of stratum losses caused by pipe roof construction:control countermeasures of stratum losses caused by support deformation.The engineering example was provided to prove the effectiveness of the control countermeasures.