土工合成材料土中拉伸试验研究

Research on In-soil Tensile Test of Geosynthetics

土工合成材料加筋技术在工程中的应用日益广泛,但其试验手段还显得相对单一,如土工合成材料的拉伸性能往往在空气中进行测试,与实际工程中的土中受力条件有较大差别。本文通过研制的多功能土工合成材料土中拉伸试验机,测试了五种不同土工合成材料的土中拉伸性能及其在四种法向荷载下的表现。结果表明:土工合成材料土中拉伸试验与空气中的差别巨大,尤其对于无纺土工织物。由于两侧土体对拉伸材料施加的法向荷载相当于给予了侧限的作用,拉伸试验中的割线模量具有较大的增大。

The soil-reinforcement technology in geosynthetics has become a wildly acceptable approach for constructing soil structure. Homever,the test technique for the geosynthetics is much backward compared with engineering application.For example,there are significant differences between the results of regular tensile test in air and in-soil tensile test for the geosynthetics.In this paper,study on the tensile response test of geosynthetics in-soil using a new developed multifuncational geosynthetics in-soil tensile apparatus under different confinement conditions is done.The in-soil tensile properties of five different geosynthetics under four normal loads are tested. The results show that the differences of test curves between in-air and in-soil tests are big,especially for nonwoven geotextile as reinforce.Because the normal loading on both sides of tensile materials equals a function of side confinement,the secant modulus of geosynthetic incrase significantly.