Destroy energy dissipation characteristics of cement-tailings backfill under splitting tensile condition
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摘要: 應用INSTRON剛性伺服試驗機對不同灰砂比的充填體進行了劈拉試驗,測得荷載-位移和應力-應變全曲線.結合測得的力學參數計算出相關能量耗散特征參數,分析了不同情況下破壞過程的能量耗散變化規律,并通過數據統計回歸建立了各種能量耗散指標與其影響因素的函數關系.實驗結果顯示:充填體只需吸收極少能量即可滿足拉伸破壞所需,拉伸破壞是影響充填體斷裂性質的主導因素.為防止充填體處于受拉環境,在礦房回采時應采用邊孔控制爆破和不耦合裝藥,優化爆轟波破巖途徑,減少欠挖超挖,保證礦柱形態規整,使充填體處于非拉區域以改善其受力狀況;同時在礦房充填時應對需布設工程或應力集中區域等關鍵部位適當加大灰砂比,以增強充填體吸收破壞能量的能力.Abstract: A series of splitting tensile tests were conducted by using an INSTRON testing system to investigate the effect of cement-tailings ratio on the properties of backfill. Based on experimental data, the evolvement laws of energy dissipation under different conditions were presented and some correlative formulae were proposed to describe the relationship between energy dissipation and influencing factors, It was found that tensile failure acted as the dominant factor for eventual failure of backfill and energy was dissipated less for tensile failure. Several optimized measures were suggested to reduce, even eliminate, the tensile state in backfill. Control blasting of periphery-holes and decoupling charging should be used to reduce under-excavation and over-excavation by optimizing the propagation of detonation wave. Crucial parts, where projects are disposed and stress concentrates, should be reinforced by special backfill with large cement-tailings ratio to improve the energy absorption capacity of the structure.
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Key words:
- concrete material /
- splitting tensile /
- energy dissipation /
- rigid testing machine
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