Application Research Of Coastal Soft Foundation By Low-Energy Dynamic And Dewatering Consolidation

Soft clay foundation characterizes high natural water content， large natural viodratio， low shear strength， high compressibility factor. Due to the small permeabilitycoefficient and poor drainage capacity，the ground strength value is small.Therefore，reasonable treatment to soft ground in engineering construction must be chosen，otherwise foundation strength and security of the superstructure will be hard toensure.In this thesis， High-tech Industrial Development Zone in Qingdao is taken as anexample. Considering the features of soft foundation in high-tech industrialdevelopment zone of Qingdao and requirement of short construction period， thetopic uses a low-energy dynamic and dewatering consolidation method for thefoundation treatment. This paper mainly studies as follows:1. In this paper， the mechanisms of the dewatering method， the low-energydynamic compaction method， the low-energy dynamic and dewatering consolidationmethod are investigated. The pore water pressure resulting from compaction andnegative pressure generated by dewatering， which can quickly dissipate the excesspore water pressure. Combination with each other can shorten the construction periodand avoid "rubber soil"， which can reduced the construction costs greatly.Therefore， the low-energy dynamic compaction and dewatering together is used insoft foundation improvement， which can not be compared with the advantages ofother method.2. Take an example of High-tech Industrial Development Zone in Qingdao， thewriter conducted field trials and monitoring. Analysis of the construction process，for example，surface subsidence，stratified settlement，pore water pressure，waterlevel changes and soil test data before and after construction， CPT experimentaldata， standard penetration test data， using low-energy dynamic compaction anddewatering method is feasible for treatment of soft ground. The economy is better，significantly shorten the construction period， and can meet the design requirements， to achieve good reinforcement effect， The method can be used for large soft handle.3. Based on the site condition， a finite difference calculation model was built toanalyze the law of distribution and dissipation of pore water pressure along depth atanytime (with the basement undrained)， under impact load of single hammer.Schematic diagram of surface displacement and shape of pit under impact load.