Research On Dynamic Compaction Technology Of Vehicle Moving Platform Base

Transfer platform is a shallow pit type rail vehicles,which the main carrier of bullet train in different plant maintenance base maintenance.Because the transfer platform for large equipment,and the upper part of the large maintenance vehicles,their own weight and the upper load are larger,so for the lower part of the vehicle carrying capacity requirements are very high.The project for the city of Zhengzhou CSR rail transportation equipment manufacture and maintenance base construction project(?),the site is located in the northern part of Zhengzhou Xing Yang City,Science Avenue and Ying Guang road intersection southwest corner of the site to the west,for the planning of Guang Wu lu.According to the engineering geological exploration of the project file,clear the position of geological conditions of Taiwan based car moved into non weight collapsible venues,handling of the transfer platform foundation selection,the final decision to use the dynamic compaction scheme for foundation.Based on the dynamic compaction of the foundation of the platform,this paper summarizes the design parameters,construction technology and the quality inspection of the non self weight collapsible loess foundation by dynamic compaction method are summarized:(1)The transfer platform is a large equipment for the maintenance of the vehicle,which has strict requirements on the bearing capacity and settlement of the foundation.The project transfer platform to maintain the normal operation of the rail top surface must satisfy the joint gap less than 2mm,the height difference is less than or equal to track important technical indexes of 2mm and 1.2mm,joint lateral track vertical dislocation of less than 2mm and a gauge deviation of-2mm ~ +3mm requirements.(2)According to the project investigation report transfer platform based on collapsible loess foundation treatment depth thickness of 6m and 10 m under the ground,the bearing capacity of 100 kPa design requirements of soil compaction is0.94.After the selection of dynamic compaction treatment program,the dynamiccompaction method of the lowest cost of 25 yuan /2m,the construction period is relatively short 26 d,the construction method is simple and easy to ensure the quality of construction,compaction and bearing capacity of the two indicators to meet the engineering design requirements.(3)After the dynamic compaction treatment,the dry density of the soil is improved obviously,the maximum dry density of 1.89 g/3cm is 11.6% corresponding to the optimum water content,the optimum moisture content is consistent with the stability of the soil mass after non weight collapsible loess,soil compaction coefficient is more than 0.94,to meet the design requirements of the foundation of transfer platform,achieve the desired effect.(4)The transfer platform soil when loading pressure reaches 100 kPa,the maximum settlement of 4.63 mm dynamic compaction,the minimum settlement of1.19 mm,the average settlement of 3.43mm;the cone resistance of soil static penetration detection is greater than the side friction resistance of 2MPa,not less than40 kPa,the change of friction than n in 1.5 ~ 4 between that soil cone resistance equivalent consolidation treatment after the value of not less than 1.5MPa.(5)Dynamic compaction construction settlement monitoring and dynamic layered soil subsidence monitoring,foundation the dynamic compaction soil compaction click the largest 28 cm,with the increasing in the number of tamping,the final cumulative settlement of 110cm;After compaction of each layer soil settlement size are different,the first and second layers of larger settlement the largest,up to24 mm,while the third layer and fourth layer soil subsidence change is small,the values are 18 mm and 12 mm,about 1000 h of the soil settlement is stable,the amount of 30 mm the maximum settlement after construction.