Risk Analysis And Assessment During Construction Of Shallow Tunnel And Underground Engineering In Urban Area

Although the technology of the Shallow Tunnel Construction Method used in city tunnel and underground engineering is very mature, because of the uncertainties of the hydrological and geologic condition and the complexcity of the construction environment, many construction risks are existing and many accidents have happened. Through a lot of literature looked up to and in-depth analysis and research, research methods including academic analysis and calculation, research on model test, research on field test, numerical simulation and literature search are used in allusion to the characteristic of the risk in city tunnel and underground engineering:1. Risk evaluation system in city tunnel and underground engineering composed of risk evaluation index system, risk evaluation rule and risk evaluation procedure is put forward first.2. A suit of index system which is orbicular in some degree and accord with the characteristic and risk speciality of the city tunnel and underground engineering as well as calculation method of risk evaluation index in every stage is set up.3. References of risk assessment was proposed firstly according to the research on criterion of risk assessment at home and abroad, which should be: composition concept of risk assessment technology criteria and risk acceptance criteria; risk acceptance criteria that was firstly established suitable for feature and risk characteristic of city tunnel as well as underground works.4. According to the construction characteristic of the city tunnel and underground engineering, work flow suitable for rist evaluation of construction of the Shallow Tunnel Construction Method in city tunnel and underground engineering is set up.5. According to the statistical analysis of surface sedimentation values that were measured in Beijing subway constructed by shallow tunneling method, statistical law of ground movement and deformation caused by city tunnel and underground works construction in Beijing subway using shallow tunneling method was summarized.6. Based on statistical law of ground movement and deformation as well as analysis and research on interaction and mechanical response between underground pipeline and bridge, risk assessment technology criteria suitable for the effect among surface installations,underground pipeline and bridge due to construction by shallow mining method was proposed, and risk assessment program was also established on it. Meanwhile, we verify the research thought and results combined with practical work.