Analysis And Evaluation Of The Utilizability Of Rock And Soil Mass In Chang Chun City Downtown Underground Space

With the development of economy, the Civil construction of underground space isprogressively increasing. Some local government introduced the planning provisionsabout the development and utilization of underground space. Many large andmedium-sized city constructed the underground space very well. Since2010, the ChangChun government has planned and constructed the NO.1subway in Chang Chun City,which will promote the economic development and engineering construction in thesurrounding area. Right now it is significance for carrying out the availibility research ofrock and soil mass in Chang Chun City underground space. The availibility of rock andsoil mass in urban underground space is carryed out from the view of engieering geology,comprehensively analysis the engineering geology characteristics of rock and soil mass,analysis and judge the feasibility of underground construction. The main analysis contentincludes the distribution of rock and soil mass in underground space, the engineeringgeology characteristics, and the feasibility for the excavation and construction in differentdepth of underground engineering such as foundation engineering, foundation pitengineering, underground chamber. The division and evaluation of the availibility of rockand soil mass in urban underground space can aid the urban planning design. Thus caneffectively use the stratum with a well engineering geology characteristics, avoid the landresources tense and waste, decrease the unnecessary redo construction in undergroundengineering, and decrease the economic loss of improper land use.The paper collected about thousand borehole informations of Chang Chun citygeotechnical engineering investigation. Comprehensively analysised the rock and soilmass distribution and engineering geology characteristics in the depth range of30m belowthe Chang Chun downtown surface. In principle, the formation lithology in Chang ChunCity is very well. The distribution of stratum is relatively uniformity and single. There isno large-scale soil distribution. The adverse geologic phenomena is relatively less. So theChang Chun City is suitable for the development of underground space construction.For rapidly withdraw and storage magnanimity geotechnical engineeringinvestigation data, the paper analysised the existed data structure type, based on the theme of underground space exploitation, used the CASE tool of Power Designer to construct theChang Chun City downtown engineering geology data warehouse model and achieved thedata storage in Microsoft SQL2005.The paper adjusted the sourc borehole data based on the macroscopic engineeringgeology stratigraphic sequence, used the GOCAD to construct the Chang Chun Citydowntown3D visualization engineering geology model. The analysis of lacuna in themodel can particularlly describe the stratum distribution of Chang Chun City.The paper analysised the key factors of Chang Chun City downtown undergroundspace exploitation from several aspects such as engineering geology, human engineering,hydrogeology, and earthqueke. From the construction type and human activity intensitypoint of view, the paper respectively discussed the factors of the availibility of rock andsoil mass in superficial zone of0~3m below the surface, and in3~15m middle zone,15~30m deep zone. The paper use the rough set theory to significance assess and reductthe factors in different underground spaces. Use the FAHP to calculate the weight ofreduced factors. And use the extenics theory to evaluate the utilizability of rock and soilmass in different underground spaces.Through the reserch of the availibility of rock and soil mass in Chang Chun Citydowntown underground spaces, the paper acquired achievement and conclusion as below:1. Concluded the comprehensive engineering geology in reserch area. Separate thestratum in research area into two engineering geology unit by the Yi Tong river whichranges running north and south in the reserch area, namely the second-step platformunit in the weat Yi Tong river and the first terrace unit in the east Yi Tong river.2. Analysised the key factors of Chang Chun City downtown underground spaceexploitation from several aspects such as engineering geology, human engineering,hydrogeology, and earthqueke.3. Divided the Chang Chun City downtown underground spaces into three zones:0~3msuperficial zone,3~15m middle zone,15~30m deep zone. Respectively choosedcorresponding factors for different underground spaces by the construction types androck and soil mass distribution.4. Constructed Chang Chun City downtown engineering geology data warehouse, whichcan rapidly and effectively withdraw data from the backup in Li Zheng geotechnicalengineering investigation software.5. Constructed Chang Chun City downtown3D visualization engineering geology model,which can perceptual intuitively observe the distribution of Chang Chun Citydowntown stratum.6. Use the rough set theory to reduct the factors of the availibility of rock and soil massin different underground spaces. The reducted factors is representative, and reducedthe caculation time.7. Use the extenics theory to evaluate the utilizability of rock and soil mass in ChangChun City downtown underground spaces. The result is meaningful and available.