Design method of pile-slab structure roadbed of ballastless track on soil subgrade
来源期刊：中南大学学报(英文版)2013年第7期
论文作者：ZHAN Yong-xiang(詹永祥) 姚海林 JIANG Guan-lu(蒋关鲁)
文章页码：2072 - 2082
Key words：soil subgrade; ballastless track; pile-slab structure roadbed; load combination; dynamic model test
Abstract: Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it is proposed to carry out load effect combination according to ultimate limit state and serviceability limit state, and the most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure. Space model of pile-slab structure can be simplified as a plane frame model, by using the orthogonal test method, and the design parameter of pile-slab structure is optimized. Moreover, based on the engineering background of Suining-Chongqing high-speed railway, the dynamic deformation characteristics of pile-slab structure roadbed are further researched by carrying on the indoor dynamic model test. The test results show that the settlement after construction of subgrade satisfies the requirement of settlement control to build ballastless track on soil subgrade for high-speed railway. Slab structure plays the role of arch shell as load is transmitted from slab to pile, and the vertical dynamic stress of subgrade soil is approximately of “K” form distribution with the depth. The distribution of pile stress is closely related to soil characteristics, which has an upset triangle shape where the large dynamic stress is at the top. Pile compared with soil shares most dynamic stress. Pile structure expands the depth of the dynamic response of subgrade and improves the stress of subgrade soil, and the speed of train has limited effect on dynamic response. These results can provide scientific basis for pile-slab structure roadbed used on soil subgrade.
ZHAN Yong-xiang(詹永祥)1, 2, YAO Hai-lin(姚海林)1, 2, JIANG Guan-lu(蒋关鲁)3
(1. Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China;
2. State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and soil Mechanics,
Chinese Academy of Sciences), Wuhan 430071, China;
3. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China)
Abstract:Pile-slab structure roadbed is a new form of ballastless track for high speed railway. Due to lack of corresponding design code, based on the analysis of its structure characteristics and application requirements, it is proposed to carry out load effect combination according to ultimate limit state and serviceability limit state, and the most unfavorable combination of each state is chosen to carry through design calculation for pile-slab structure. Space model of pile-slab structure can be simplified as a plane frame model, by using the orthogonal test method, and the design parameter of pile-slab structure is optimized. Moreover, based on the engineering background of Suining-Chongqing high-speed railway, the dynamic deformation characteristics of pile-slab structure roadbed are further researched by carrying on the indoor dynamic model test. The test results show that the settlement after construction of subgrade satisfies the requirement of settlement control to build ballastless track on soil subgrade for high-speed railway. Slab structure plays the role of arch shell as load is transmitted from slab to pile, and the vertical dynamic stress of subgrade soil is approximately of “K” form distribution with the depth. The distribution of pile stress is closely related to soil characteristics, which has an upset triangle shape where the large dynamic stress is at the top. Pile compared with soil shares most dynamic stress. Pile structure expands the depth of the dynamic response of subgrade and improves the stress of subgrade soil, and the speed of train has limited effect on dynamic response. These results can provide scientific basis for pile-slab structure roadbed used on soil subgrade.
Key words:soil subgrade; ballastless track; pile-slab structure roadbed; load combination; dynamic model test
