Residual deformation of coal gangue subgrade filler under multi-vibration cyclic loading

Abstract

In this paper, the development law of residual deformation of coal gangue subgrade filler is analyzed through large scale triaxial test, and the residual deformation model of coal gangue mainly sandstone and limestone is established. The purpose is to provide research basis for the applicability of coal gangue as subgrade filler. The results show that the deformation of coal gangue filler increases first and then tends to be constant under cyclic load of multiple vibration times. It is found that the Shenzhujiang residual deformation model cannot accurately predict the deformation law, and the corresponding modification is made to the residual deformation model of coal gangue filling body. Finally, according to the calculation of grey correlation degree, the influence degree of main factors of coal gangue filler on its residual deformation is sorted. Combined with the actual engineering situation represented by these main factors, it can be analyzed that the effect of packing particle density on residual deformation is greater than that of packing particle size composition.

Study on the Particle Strength and Crushing Patterns of Coal Gangue Coarse-Grained Subgrade Fillers

“…A curve, similar to the first type, with some troughs reaching zero appears. 3 ⃝ The curve shows approximately linear growth, and failure occurs at small displacements, exhibiting the characteristics of brittle rock failure.…”

“…At present, the coal gangue accumulated on the ground of mining areas in China has exceeded 6 billion tons, becoming the largest industrial solid waste in China [1,2]. Coal gangue associated with coal seams during the coalification process is a hard black or gray rock with low carbon content [3]. Thus, it can be used as aggregate in concrete and subgrade fillers [4].…”

“…Therefore, before backfilling, the large particles are usually crushed to ensure that the pores between large particles in subgrade filler can be completely filled by fine particles, thereby ensuring the long-term performance of the subgrade. Some research results have been achieved on the performance of coal gangue as road subgrade filler, for example, Tang et al [3] studied the residual deformation of coal gangue subgrade filler through large-scale triaxial tests, and established a calculation model. Li et al [12] measured the basic properties of coal gangue such as particle size distribution, ignition loss, strength change under water softening, and compression performance and put forward the technology to use coal gangue as filler in railway subgrade and demonstrated that a coal gangue roadbed had excellent performance, meeting the requirements for highspeed railway roadbeds.…”

Dynamic characteristics of coal gangue subgrade filler under traffic load based on the hysteretic curves

“…Zhang et al 1 investigated the permanent deformation and its unified model of coal gangue subgrade filler under traffic cyclic loading. Tang et al 22 studied the residual deformation of coal gangue subgrade filler under multi-vibration cyclic loading. In addition, the effect of gradation on the compaction and strength characteristics of coal gangue subgrade filler was also studied 17 , 23 , 24 .…”