Study On Three-dimensional Engineering Geological Structure And Suitability Of The Underground Space In Harbin’s Key Region

At current，the trend of urban development is stretching around outside urban whichgradually increase the construction space of the urban area and the speed of thedevelopment,therefore,there is a need on research of more comprehensivethree-dimensional engineering geological conditions. At the same time, the contradictionamong the high speed development of economy, traffic congestion, lack of space, airpollution in Harbin become increasingly serious， seriously restricting the urbandevelopment and the improvement of environmental quality，finding out the engineeringdevelopment suitability in shallow underground space from0to10m and from10to30mis significant for the reasonable, orderly and sustainable development of the undergroundspace resource in Harbin，and making full use of underground space resource is thefavorable condition of the city high speed and stable development.Based on the full understanding of natural geography, economic status and regionalgeological background in key region of Harbin, and using the material of field drilling andindoor geotechnical test data processing from the geotechnical body three-dimensionalengineering geological structure and the underground space resource investigation whichis one project of the urban geological survey, to carry out the engineering geologythree-dimensional structure research, And on this basis, combining with the existence ofbad geological body and underground water distribution characteristics, to carry out thezoning of engineering geology, on finding out the engineering geology three-dimensionalstructure and geological zoning basis, to make up the establishment of underground spaceproject difficulty evaluation model that based on analytic hierarchy process (ahp) ofmultiple factors weight index function method, and using this model to find out theunderground space Suitability evaluation within the fourth ring region in Harbin. Based on analysis of drilling formation and physical properties index, the Quaternarystrata that stretch from4.5to108.1m in thickness in Harbin’s key region is divided intotwelve main layers, forty-six sub layers and seven secondary sub layers. combined withthe stratigraphic age, lithology and causes of formation of rock mass and soil, the paperfind out the engineering geology three-dimensional structure types which are divided intothree categories which are single layer structure, double layer structure and multilayerstructure. The single structure can be divided into single cohesive soil and single inviscidsoil. The double layer structure can be divided into three types which are thick layer ofcohesive soil in the upper layer and inviscid soil in the lower layer, medium thick cohesivesoil in the upper layer and inviscid soil in the lower layer, and the thin layer viscous soil inthe upper layer and inviscid soil in the lower layer. And the multilayer structure can bedivided into three types which are multilayer structure distributing thick cohesive soillayer, medium thickness cohesive soil layer and inviscid soil layer in the upper.According to the engineering geology conditions of Harbin, engineering geologicalzone divided in three levels. Based on landform genetic types and causes for the first leveldivision, determined the engineering geology area; Then according to the geomorphic unitand regional crustal stability for the second level division, determined the engineeringgeology sub-area; According to the site engineering geological condition divided the areainto five section. That is excellent section, good section, medium, poor section, poorersection, eventually work region can be divided into three engineering geology area,10engineering geology sub-region,19engineering geological section.Results of suitability zoning of underground space within the fourth ring region inHarbin show that Shallow underground space can be divided into the suitable division,better suitable, medium suitable area, and the deeper Shallow underground space can bedivided into the better suitable area, medium suitable area, poor suitable area, unsuitablearea. The data provides an important geological basis for economic construction,municipal planning and the resources reasonable use of Harbin.