Experimental Investigation of the Bearing Performance and Failure Characteristics of Double-Row Pile-Slab Structures in Steep Mountainous Areas

Abstract

Considering the pile-slab subgrade project of the Hangzhou-Huang Shan Passenger Dedicated Line as the basis, this paper conducts a 1:10 large-scale indoor model test for the horizontal bearing capacity of the pile-slab structure in steep mountainous areas to study the distribution of the pile-slab structure stress, soil pressure and structural deformation and analyze the failure mode of the structure and slope. The research shows that when the subgrade with a double-row pile-slab structure is subjected to horizontal loading in the steep slope section, the steel bars of the pile body above the sliding surface are compressed, and the steel bars of the pile body below the sliding surface are under tension. With the increase in the horizontal load, the stress of the pile body steel bar remains basically unchanged or shows a steady increase and finally sharply increases. The deformation of the bearing plate isdominated by the horizontal displacement, and the horizontal displacement reaches 7.25 mm when the plate is broken. In addition, warping deformation of the inner high and outer low occurs. When the horizontal load reaches 157 kN, shallow damage and local collapse of the slope occur, and transverse and diagonal cracks occur at the top of the pile and near the sliding surface of the pile. During the test, the pile-slab structure always deforms more than the slope, and the overall stability of the structure is good. The test is suitable for sections where the remaining sliding force is less than 770 kN/m (equivalent to a slope length of 79.123 m).

Keywords

• bearing performance
• failure characteristic
• high-speed railway subgrade
• indoor model test
• pile-slab structure
• steep slope