The simulating exactly compared with realty of ground surface to run a model is more and more highly required. In the real, terrain of the earth surface is always complicated by the natural and human made ground objec...The simulating exactly compared with realty of ground surface to run a model is more and more highly required. In the real, terrain of the earth surface is always complicated by the natural and human made ground objects. Because of limitation of collecting and storing technologies in the past time, data are usually not detailed so that the data can not be full for the simulation. Besides computing power and simulation increase more day by day, the increasing requirements more detailed of topography surface simulation is a demand. In simulated flooding phenomenon or phenomena related to energy and momentum of water flow, the linear objects of ground surface such as roads, dikes, dams, etc. need to have their vertical dimension along continuously. However, these datas have often no height information alternately, there are only discrete elevation points that are extracted from topographic maps. Consequently, the demand of a suitable method for linear objects height interpolation is necessary. This paper aims to provide a method and evaluate its accuracy to meet this requirement.展开更多
City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dis...City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.展开更多
文摘The simulating exactly compared with realty of ground surface to run a model is more and more highly required. In the real, terrain of the earth surface is always complicated by the natural and human made ground objects. Because of limitation of collecting and storing technologies in the past time, data are usually not detailed so that the data can not be full for the simulation. Besides computing power and simulation increase more day by day, the increasing requirements more detailed of topography surface simulation is a demand. In simulated flooding phenomenon or phenomena related to energy and momentum of water flow, the linear objects of ground surface such as roads, dikes, dams, etc. need to have their vertical dimension along continuously. However, these datas have often no height information alternately, there are only discrete elevation points that are extracted from topographic maps. Consequently, the demand of a suitable method for linear objects height interpolation is necessary. This paper aims to provide a method and evaluate its accuracy to meet this requirement.
基金Project supported by the National Basic Research (973) Program of China (No. 2010CB732105)the National Natural Science Foundation of China (Nos. 50908193,50925830,and 51208432)
文摘City metro tunnels are usually constructed as twin-parallel tunnels and their adjacent construction may lead to surface deformation,affecting the surface environment and the safety of the tunnels.Due to its strong dispersion,sandy cobble strata can be easily disturbed by shield tunneling.Based on the project of the Chengdu Metro Line 1,field and model tests were carried out to study the surface settlement caused by shield tunneling in sandy cobble strata by measuring surface settlement curves,ground loss ratios and construction influence zones.The discrete element method(DEM) was used to study the factors affecting the formation of ground arches in sandy cobble strata at the microscopic level.Results show that the shape of the surface settlement curve in sandy cobble strata is different from that in soft soil.The buried depth and clear spacing of the two tunnels had a significant impact on the formation of ground arches.
