摘要
预应力锚索加固技术已经得到了广泛的应用,但目前对锚索预应力锁定后的变化规律还缺乏系统深入的研究,特别是对破碎岩质边坡锚固预应力的瞬时损失和长期稳定性还缺乏系统全面的认识。通过对工程边坡锚固索体预应力变化的系统监测和资料分析,探讨了锚索预应力的锁定损失、短期变化规律、长期变化规律和降雨对锚索体有效预应力的影响,揭示了破碎岩质边坡锚索预应力衰减变化的基本规律。
另外,针对锚索预应力受坡体介质材料蠕变影响造成的长期损失,对此建立了相应的力学分析模型,进行理论分析,同时也运用有限元对此进行建模分析,其结果与已有试验结果相比较都较符合,验证了理论模型及有限元模型的适用性。通过理论分析,不仅可以在已知坡体介质材料蠕变参数的情况下,对锚索预应力长期变化进行估计,也可以对已有的锚索预应力实测数据进行反分析,反演坡体的蠕变参数,具有较高的工程应用价值。
Though it is widely used in projects with anchorage cable, the prestress change rules of the cable are still not researched thoroughly and systematically, especially the prestress loss after lock and the lasting prestress of cable in cracked rock slopes. Based on the systematically monitoring and analysis in a slope reinforcement project, the prestress loss after lock, short-term, as well as long-term prestess change rules are studied, and also the influence of rainfall to the cable prestress state is monitored and discussed. It is found that the prestress loss after lock is largely based upon the shrink of the anchorage cable after lock, but the friction can to some degree infect this shrink quantity. The short-term prestress loss is nonlinear, the same is the long-term prestress loss m ost o f w hich c an b e div ided int o t hree s tages. T he influence o f rain t o t he prestress loss should be considered respectively. If the slope is not stable, the rain can infect the stabilization of the slope and the
n infect the prestress state of the anchorage cable, otherwise, it has no infection to the prestress state.
As to the long-term prestress loss of the cable, which is due to the creep of the medium materials, new mechanical modal was established, and the change rules were analyzed. It was also analyzed with finite element method. The two results were both tally with the results of the experiments, which proved the applicability of the modals. With the theoretical analysis or finite element method, not only the long-term change rules of the cable prestess can be estimated, when the creep parameters are known, but also the creep parameters can be computed by analyzing the prestress loss data got from actual projects.
引文
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