关键词: 充填体, 分层效应, 初始分层损伤, 损伤本构模型, 强度准则

Abstract: With horizontal slice backfilling of mines as the background, three concepts, namely initial stratified damage, loaded damage and total damage, were put forward for horizontal stratified cemented backfill. Based on the damage mechanics theory, the damage evolution model and the damage constitutive model were built with the consideration of the stratification effect. Based on the method of full differential function, a strength criterion of backfill, which considered the effect of stratified structure, was established. Then, tests to investigate the mechanical properties of backfills with different number of layers were conducted. Based on the results of tests, several conclusions can be drew. The theoretical curve of the damage constitutive model and the strength criterion fit the experimental results well, which verifies the correctness of the newly proposed models. The initial stratified damage increase at a quadratic polynomial function with the increase of the number of layers. The total damage of backfills is aggravated by the coupling effect of stratification and load. The total damage rate of backfill tends to firstly increase and later decrease. Before the peak, the total damage rate increases with the increase of the number of layers; after the peak, the total damage rate decreases with the increase of the number of layers, while the maximum of total damage rate increases with the increase of the number of layers.

Key words: backfill, stratification effect, initial stratified damage, damage constitutive model, strength criterion