土工合成材料流变参数合理选择的研究

发布时间：2018-01-04 01:03

本文关键词：土工合成材料流变参数合理选择的研究　出处：《岩土工程学报》2015年03期 　论文类型：期刊论文

【摘要】：工程中应用土工合成材料时必需考虑其流变特性的影响,流变特性一般指蠕变、松弛、长期强度等方面的性质。当前在土工合成材料设计强度值的选择中,为考虑蠕变影响,往往对其极限强度乘一个蠕变折减系数后加以使用。这个系数如何取值对工程的安全性和经济性影响很大。由于对该系数研究不够,国际和国内都存在很大分歧,一般都取得十分保守。土工合成材料蠕变试验成果表明,蠕变的影响与作用的荷载水平关系很大,当荷载水平小于某一临界值时,材料的变形将渐趋稳定,不会导致蠕变破坏。而根据国内外大量工程实测资料表明,加筋土结构中筋材所受的力很小,仅及设计预测值的几分之一,甚至只有5%,变形也远低于预测值,筋材最大的受力和变形发生在施工结束时。同时,实测资料表明,土体中筋材存在松弛现象,它将减轻蠕变的影响。根据有关的机理分析、试验数据和实测资料,对筋材强度折减系数的合理取值提出了建议。
[Abstract]:In engineering application of geosynthetics, the influence of rheological properties must be considered. The rheological properties generally refer to the properties of creep, relaxation, long-term strength, etc. At present, the design strength of geosynthetics is chosen. In order to consider the creep effect, it is often used to multiply the ultimate strength by a creep reduction coefficient. The value of the coefficient has a great influence on the safety and economy of the project. The creep test results of geosynthetics show that the influence of creep is closely related to the load level, when the load level is less than a critical value. The deformation of the material will gradually stabilize and will not lead to creep damage. However, according to a large number of engineering data at home and abroad, the force of reinforced soil structure is very small, which is only one part of the predicted value of design. Even if only 5, the deformation is far lower than the predicted value, the maximum force and deformation of the reinforcement occurred at the end of the construction. At the same time, the measured data show that there is relaxation of the reinforcement in the soil. It will reduce the influence of creep. Based on the analysis of relevant mechanism, experimental data and measured data, the reasonable value of strength reduction coefficient of steel bar is suggested.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;
【基金】：中央级公益性科研院所基本科研业务费资助项目(CKSF2014060/YT))
【分类号】：TU531.7
【正文快照】： R e s o u r c e s,W u h a n 4 3 0 0 1 0,C h i n a)0问题的提出土工合成材料属人工聚合物,它具有一般聚合物常有的流变特性,即在外荷作用下,其应力、应变和强度特性会随时间而变化。当工程中应用这种材料时,为考虑这种特性的影响,需要对材料的性能指标进行一定的折减。比如

【参考文献】