CAJ | 학술논문

目前加筋土结构设计中筋材的抗拉强度都是根据室内标准无约束拉伸试验而得到的，不能反映筋材与土存在相互作用下的真实力学特性。采用土工格栅进行了一系列模拟加筋土实际受力状态的侧限约束拉伸试验和蠕变试验，结果表明，常规无约束条件下获得的格栅抗拉强度与实际情况相差很大，不同类型土工格栅在砂土侧限约束下的拉伸强度和延伸率变化规律与上覆荷载及拉伸速率有关，但割线模量都比无约束情况下有显著增大；侧限约束下格栅的蠕变量明显降低。因此，在加筋土结构设计中，筋材的抗拉强度指标宜采用符合工程实际受力状态的侧限约束拉伸试验强度值。另外，以无约束试验得到的筋材蠕变安全系数过于保守，侧限约束下筋材的蠕变临界应力水平有所提高。
목전가근토결구설계중근재적항랍강도도시근거실내표준무약속랍신시험이득도적，불능반영근재여토존재상호작용하적진실역학특성。채용토공격책진행료일계렬모의가근토실제수력상태적측한약속랍신시험화연변시험，결과표명，상규무약속조건하획득적격책항랍강도여실제정황상차흔대，불동류형토공격책재사토측한약속하적랍신강도화연신솔변화규률여상복하재급랍신속솔유관，단할선모량도비무약속정황하유현저증대；측한약속하격책적연변량명현강저。인차，재가근토결구설계중，근재적항랍강도지표의채용부합공정실제수력상태적측한약속랍신시험강도치。령외，이무약속시험득도적근재연변안전계수과우보수，측한약속하근재적연변림계응력수평유소제고。
At present, the design tensile strength of reinforcement in reinforced soil structure is determined by indoor tensile tests in air, but such kind of unconfined tensile tests are inconformity with the real state of reinforced soil structure. A series of sand-confined tensile tests and confined-creep tests of geogrids were carried out. The testing results indicate that the real mechanical property of reinforcement in soil is quite different than those by the conventional unconfined tests. The changing rules of strength and elongation of different geogrids are related with vertical ftress and tensile rate, but the secant modulus have significant increase than the unconstrained cases. Besides, the confined-creep decreases obviously. Therefore, the sand-confined tensile strength of geogrids should be adopted as the reference value of design strength in reinforced soil structure. Moreover, the traditional factor-of-safety for creep is too conservative because confined-creep critical stress level has increased.