Designed And Stability Analysis On Deep Foundation Pit Support In Coastal Soft Ground

Based on the deep foundation pit project of OCT Hotel in Shenzhen Bao'an Binhai Cultural Park Binhai Park,the deformation characteristics and stability of the supporting structure of deep foundation pit was studied in coastal soft soil area.The proposed site has a thick soft soil layer and complicated geological conditions,which makes it difficult for the support and construction of deep foundation pits.The paper aimed to guide the engineering practice and provide reference for the deep foundation pit engineering of similar geological conditions in the future.The main conclusions were:1.The deformation mechanism of the deep foundation pit supporting structure was deeply analyzed,and the lateral deformation mode of the foundation pit supporting structure in soft soil layer was the kicking deformation mode.At the same time,the evaluation criteria for the stability of the foundation pit support structure are determined.2.Through a variety of support schemes,the deep foundation pit support scheme of OCT Hotel was determined,namely,grading + single row pile(inner support)+ double row cement mixing pile water stop curtain;based on the internal force calculation theory of support structure,the support structure parameter was designed completely.3.The FLAC numerical calculation method was used to analyze the deformation characteristics of the deep foundation pit supporting structure in soft soil area,and the rationality of the supporting scheme is verified.The calculation results showed that the deformation of the deep foundation pit support structure in the soft soil layer was quite different from that of the general deep foundation pi.4.The on-site monitoring program design was completed and measured.The results showed that the deformation of the supporting structure was within the allowable range.5.According to the stability criterion of foundation pit support structure,the stability ofdeep foundation pit supporting structure of OCT Hotel was judged.The results showed that during the construction of the foundation pit,the supporting structure was stable and meets the construction requirements,which further indicated that the theoretical analysis methods,numerical calculation methods and on-site measurement schemes used in this paper were reasonable and effective.