掺早强剂全尾砂胶结充填体的动静态力学特性试验

发布时间：2018-03-10 05:23

本文选题：胶结充填体　切入点：早强剂　出处：《江西理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：在分层充填采矿技术中,提高充填体早期强度对提高矿山安全程度、缩短采充循环间隔时间具有重要意义,工程实际中可通过掺入早强剂,提高充填体早期强度。但充填体在养护期间,除承受自重、围压、顶压等静态载荷外,还承受爆破振动、冲击等动态载荷。本文针对掺早强剂全尾砂胶结充填体的动、静态力学特性开展室内试验研究。主要研究内容如下:(1)设计了32组不同早强剂掺量(0.0%、0.3%、0.6%、0.9%)、不同养护龄期(3d、7d、14d、28d)、不同试件高度(静载100mm、动载50mm)的胶结充填体动、静载力学特性试验,动载试验采用分离式SHPB试验装置,静载试验采用RMT~(-1)50岩石力学材料试验机。(2)静载条件下:充填体的抗压强度随龄期增加呈对数增大,弹性模量也随龄期增加而增大,应变则随龄期增加而减小。3天和7天时,早强剂对充填体力学特性的影响相似,随早强剂掺量增加,抗压强度增大、弹性模量增大、应变减小,且变化幅度均在早强剂掺量0.3%~0.6%时最大;但3天时早强剂对充填体抗压强度、弹性模量影响更显著,掺量为0.3%、0.6%、0.9%的充填体抗压强度分别提高了1.3、1.42、1.54倍,弹性模量分别提高了1.07、1.68、1.84倍。14天时,早强剂对各项充填体力参数影响不明显。28天时,早强剂掺量0.6%~0.9%的充填体抗压强度低于未添加早强剂组。(3)动载条件下:不同应变率时,动载抗压强度总体上随应变率增大呈指数增长关系,在7天前充填体动态强度对应变率的敏感较大,随着龄期的增长逐渐减小;且当应变率低于10 S~(-1)时充填体稳定性较好,25 S~(-1)时试件有一定的损伤裂纹,大于35 S~(-1)时裂为两块并产生贯通裂纹试件完全失稳。入射能与应变率相似,充填体单位体积吸收能与龄期呈对数增长关系。充填体的动载强度与龄期呈对数增长关系,变化趋势与静载相似,但动载强度更高,强度提高因子为1.37~2.35。早强剂对充填体力学特性的影响规律与静载相似,随早强剂掺量增加,充填体的动载强度增大、弹性模量增大、单位体积吸收能增大、峰值应变减小。3天时变化最显著,早强剂掺量为0.3%、0.6%、0.9%,充填体动载强度分别提高了1.23、1.36、1.48倍;弹性模量分别提高了1.33、2.44、3.53倍;单位体积吸收能增大了1.5、1.92、2倍;峰值应变分别减小了1.25、1.28、1.85倍。
[Abstract]:In the technology of stratified filling mining, it is very important to improve the safety degree of mine and shorten the interval time between mining and filling by increasing the early strength of the filling body. In engineering practice, the early strength agent can be added into it. But during the curing period, the filling body not only bears static loads such as self-weight, confining pressure and top pressure, but also bears dynamic loads such as blasting vibration and impact. The main contents of this study are as follows: (1) A total of 32 groups of cemented fillers with different dosages of different early strength agents (0.00. 3 and 0. 6 and 0. 9), different curing ages of 7 days, 14 days and 28 days, and different specimen heights (static load of 100 mm, dynamic load of 50 mm) were designed to test the dynamic and static mechanical properties of cemented filling body. Under static loading conditions, the compressive strength of the filling body increases logarithmically with the increase of age, and the elastic modulus increases with the increase of age. The effect of early strength agent on the mechanical properties of filling was similar with the increase of age, and the compressive strength, elastic modulus and strain decreased with the increase of the content of early strength agent. The range of variation was the largest in the range of 0.3 ~ 0.6 of early strength agent, but the effect of early strength on the compressive strength and elastic modulus of the filling was more significant at 3 days, and the compressive strength of the filling body with 0.30.36% was increased by 1.54 times, respectively. When the elastic modulus was increased by 1.07 ~ 1.68 ~ 1.84 times 路14 days, and the influence of early strength agent on the filling physical parameters was not obvious at 28 days, the compressive strength of the filling body with 0.6% of the early strength agent was lower than that of the group without the early strength agent. The compressive strength of dynamic load increases exponentially with the increase of strain rate. The dynamic strength of filling body is sensitive to strain rate 7 days ago, and decreases gradually with the increase of age. When the strain rate is lower than 10 S-1), the stability of the backfill is better than that of the strain rate. When the strain rate is less than 10 S-1), the specimen has a certain damage crack, but when the strain rate is greater than 35 S-1, the specimen is broken into two pieces and the through crack specimen is completely unstable. The incident energy is similar to the strain rate, and the strain rate is similar to the incident energy, and the incident energy is similar to the strain rate. The absorption energy per unit volume of the filling body is logarithmic increasing with the age. The dynamic load strength of the filling body is logarithmic increasing with the age, and the changing trend is similar to that of the static load, but the dynamic load intensity is higher. The strength improvement factor is 1.37 ~ 2.35. The effect of early strength agent on the physical properties of filling is similar to that of static load. With the increase of the content of early strength agent, the dynamic load strength, elastic modulus and absorption energy per unit volume increase. When the peak strain decreased by 3.3days, the peak strain changed most obviously. The dynamic load strength of the filling body increased by 1.231.36 ~ 1.48 times, the elastic modulus increased by 1.33 ~ 2.44 ~ 3.53 times, the unit volume absorption energy increased by 1.51.922 times, and the peak strain decreased by 1.25 ~ 1.28 ~ 1.85 times, respectively.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD853.34

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