| High pressure jet grouting method,also known as jet grouting method,has been introduced into China from Japan for nearly 50 years since 1970 s.Because of its wide application range of soil,convenient construction,low noise,controllable shape of consolidation body and good economic benefits,it has been widely used in building foundation reinforcement,foundation pit and slope support,dam seepage control,shield tunnel reinforcement and other aspects.However,at present,the theoretical research of jet grouting method lags behind engineering practice,and its design tends to be conservative,resulting in unnecessary waste.Taking Guanyindian Bridge construction project as an example,because of its special engineering geological conditions,The foundation treatment scheme is selected as the friction type high pressure jet grouting pile composite foundation.Firstly,the optimal scheme of foundation treatment is obtained by theoretical analysis and numerical simulation,then the design is carried out,and finally the construction and settlement monitoring are carried out.According to the foundation treatment scheme of the bridge construction project,the following work has been carried out:(1)According to the engineering geological conditions of Guanyindian Bridge site,the scheme selection of pier and abutment foundation of the bridge is analyzed and explained.(2)The finite element analysis software ABAQUS is used to establish the model of pile-soil composite foundation.The settlement,deformation,axial force of pile body,soil stress between piles and pile-soil stress ratio of friction type high pressure jet grouting pile composite foundation are analyzed by changing load,pile length,pile diameter and pile spacing.(3)According to the settlement calculation formula recommended by the code,the settlement and deformation of the composite foundation are calculated and compared with the simulated values,so as to obtain the optimal scheme of foundation treatment.(4)According to the optimal scheme of foundation treatment,the composite foundation of the site is designed and calculated.At the same time,the composite foundation model of 1/2 site is established,and the interaction between adjacent piers and abutments is analyzed and discussed.(5)The settlement deformation of Guanyindian Bridge was monitored for one year,and the settlement prediction formula of pier and abutment was deduced based on the monitoring results,and the final settlement prediction value was compared with the theoretical calculation value and simulation value.The application of friction-type high-pressure rotary jet grouting pile in the soft foundation of Guanyindian Bridge has achieved good economic benefits,which can provide reasonable reference for similar projects in the future. |
PDF Full Text Request