自嵌式砌块与双向土工格栅的摩擦强度试验研究

Test study on frictional strength of interlock blocks and two-way geogrids

在自嵌式砌块加筋挡土墙工程中,加筋与填土及自嵌式砌块的界面作用特性是最关键的技术指标,直接决定该工程的内部稳定性。通过室内拉拔试验可知,当法向应力大于24.8 kPa时,双向土工格栅会在其与上砌块后缘互锁连接接触处被拉断,而不是从混凝土砌块间被拔出,且此时双向土工格栅发挥出的抗拉强度远小于其条带拉伸情况下的抗拉强度;双向土工格栅与混凝土砌块界面间的强度包线由两段直线组成,当法向应力小于24.8 kPa时,摩擦强度随法向应力的增大而增大;当法向应力大于24.8 kPa时,摩擦强度为一常数。

The interaction characteristics of the interface between geogrids reinforcement and soil as well as geogrids reinforcement and interlock concrete blocks are the two key indexes for the stability of interlock segmental reinforced retaining walls. It is found that the two-way geogrids reinforcement would be tension fracture when the normal stress is over 24.8 kPa from the results of pullout test, and under this condition the tensile strength of the geo-grid is lesser than that when the two-way geogrid is tensed in the air. The strength envelopes is composed by two straight lines, the frictional strength between two-way geogrid reinforcement and interlock concrete blocks increases with the increase of normal stress when normal stress is less than 24.8 kPa and is invariable when normal stress is over 24.8 kPa.