单向格栅软体排顺水沉排受力特性研究

单向格栅软体排是一种以单向格栅为受力构件，自下而上由反滤土工布、单向格栅和混凝土压载块3部分组成的新型软体排结构。以长江中下游护底工程为应用场景，利用有限元法模拟单向格栅软体排在顺水沉排施工条件下的受力特性，发现随着相对移船位移、水深、水流流速和压载质量的增大，单向格栅软体排体的最大应力逐渐增大；随着水流方向与沉排方向夹角的增大，单向格栅软体排所承受的最大应力逐渐减小。在各种顺水沉排条件下，铺排船翻板下端处的单向格栅软体排受力最明显，且软体排承受的最大应力位于翻板下端的软体排宽度方向上距离两侧边缘约1 m的位置，软体排中间部位受力较小。结果表明：单向格栅软体排所承受的最大应力远低于其抗拉强度，该新型软体排结构在长江中下游护底工程中具有较好的适应性，相对于传统的加筋软体排，单向格栅软体排可减少20%以上的排布成本。

Stress characteristics of downstream sinking flexible mattress constructed with unidirectional grille

Flexible mattress constructed with unidirectional grille is a new type of flexible mattress, which is composed of three parts from the bottom to the top:anti-filtering geotextile fabrics, unidirectional grille, and concrete ballast block. Taking the revetment project in the middle and lower reaches of the Yangtze River as the application scenario, the finite-element method is used to simulate the stress characteristics of the unidirectional grille constructed flexible mattress under the condition of downstream sinking. The maximum stress of the unidirectional grille constructed flexible mattress increases with the relative displacement of the ship, the water depth, the water velocity, and weight of ballast block, while the maximum stress decreases with the increase of the angle between the water flow direction and the flexible mattress sinking direction. Under various downstream sinking conditions, the stresses obviously concentrate at the lower end of the flap of the paving ship on the unidirectional grille constructed flexible mattress, and the maximum stress is located at the lower end of the flap and about one meter away from the edges on both sides in the width direction of the flexible mattress, while the middle part of the flexible mattress is less stressed. The results show that the maximum stress of the unidirectional grille constructed flexible mattress is much lower than its tensile strength, and it presents good adaptability in the riverbed protection project of the middle and lower reaches of Yangtze River. Compared with the traditional flexible mattress made of the reinforced belt, the cost of the unidirectional grille constructed flexible mattress can reduce by more than 20%.