Optimizing Method Study Of Supporting System Of Deep Foundation Pit

Deep foundation pit is a systematic engineering which characterized by complexity. The choice of its supporting system plays an important role in the whole engineering and has a direct influence on the process, construction cost and quality, however, it is often one-side and subjective nowadays. Therefore, it is very necessary and meaningful to work out an objective, reasonable and practicable way of choosing the best supporting system, which actually should consider all the goals just like safety, convenience, economy and environment protection.Based on the Multi-target Decision Method study and the characteristics of the deep foundation pit, a systematic pattern of choosing supporting system is puts forward:First, analyzing the scheme through the combination of Foundation Pit Safety Grade and Deformation Control Grade together with certain regulations and experiences, then making sure the structural pattern of retaining and protecting scheme, monitoring items, bracing and digging scheme, water treatment scheme and the reference value of deformation limit, etc.Second, analyzing the vague elements of supporting system and then decide the best one by the result of the Fussy Comprehensive Evaluation.The article also comes up with a simplified optimizing method on the basis of fuzzy set theory to make the final scheme optimization meet the practicality of the engineering.Based on the optimizing method of supporting system of foundation pit and its simplified method, the analysis of the foundation excavation for Chuangye Dasha in Taiyuan has been performed. The result of the analysis coincides very well with the previous realistic design, which shows that the method is reasonable, effective and practicable.