确定蠕变折减系数的侧限时温叠加蠕变试验研究

发布时间：2018-05-09 22:40

本文选题：土力学 + 土工格栅蠕变　；参考：《岩石力学与工程学报》2015年S1期

【摘要】：设计设备研究土工格栅HDPE50在侧限(100 k Pa)约束和无侧限约束下的时温叠加蠕变试验。利用时温叠加原理将不同温度下的蠕变试验曲线移动形成一条光滑的主曲线准确地确定土工格栅HDPE50的蠕变折减系数。通过试验数据反算的C1,C2值验证试验的合理性。研究结果表明:侧限约束对土工格栅蠕变特性影响显著,侧限约束条件下106 h长期蠕变强度比无侧限荷载下的长期蠕变强度小37%。无侧限时温叠加蠕变试验和侧限时温叠加蠕变试验确定的蠕变折减系数RFCR1,RFCR2分别为2.4,1.8,在侧限蠕变试验中根据现有规范计算的蠕变折减系数RFCR3为1.7。同RFCR2相比,RFCR1,RFCR3作为同一工程的设计依据使工程造价分别增加17%,25%。侧限蠕变试验计算蠕变折减系数建议采用侧限约束下的拉伸强度,工程设计建议采用RFCR2。
[Abstract]:The time-temperature superposition creep tests of geogrid HDPE50 under lateral and unconfined constraints are studied. The creep test curve at different temperatures is moved to form a smooth principal curve by using the time-temperature superposition principle to determine the creep reduction coefficient of geogrid HDPE50 accurately. The rationality of the test is verified by the C _ 1 C _ 2 value of the inverse calculation of the test data. The results show that the creep behavior of geogrid is significantly affected by lateral confinement, and the long-term creep strength of 106 h under lateral constraint is 37% less than that under unconfined load. The creep reduction coefficient RFCR1 / RFCR2 determined by superposition creep test with no lateral limit temperature and lateral limit temperature superposition creep test is 2. 4 / 1. 8, respectively. The creep reduction coefficient (RFCR3) calculated in lateral limit creep test is 1. 7 according to the existing specifications. Compared with RFCR2, RFCR1 / RFCR3, as the design basis of the same project, increases the engineering cost by 17% and 25% respectively. In the calculation of creep reduction coefficient by lateral limit creep test, the tensile strength under lateral limit constraint should be adopted, and RFCR2 should be used in engineering design.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金资助项目(50778181,51178472)
【分类号】：TU472

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