单根无黏结预应力筋对加筋体力学性能的影响

采用缩尺模型试验研究了无黏结预应力加筋土技术中水平土压力的大小及分布对预应力加筋体力学性能的影响。试验采用钢砂模拟中砂，解决了缩尺模型相似比的问题。完成了两个工况的试验，一个普通加筋土工况，一个具有单根无黏结预应力筋的工况。对比分析表明：对无黏结预应力筋施加预拉力前加筋体的顶部沉降小于普通加筋体的顶部沉降，施加预拉力后却增加了顶部沉降，但在堆载后具有单根无黏结预应力筋的加筋体的竖向变形更小；随着预拉力的增加，与无黏结预应力筋相邻的玻纤格栅应变相应减小，在距离墙面板较近位置测点玻纤格栅的应变减小得尤为明显，而底部玻纤格栅应变逐渐增加，在距离墙面板较近位置测点增加得较为明显；在堆载过程中，无黏结预应力筋的预拉力保持不变，堆载完成后略有增加。

Influences of single unbonded prestressed steel bar on mechanical properties of reinforced body

The influences of the magnitude and distribution of horizontal earth pressure on reinforced body using unbonded prestressed reinforcement technique were studied through scaled model tests in the paper. The steel shot was adopted for its appropriate similarity ratio to simulate medium sand in the model test. Two cases were tested to compare the common reinforced body and the single unbonded prestressed reinforced body. The comparison shows that the settlement on the top of body with unbonded prestressed reinforcement before applying pre-tension is less than that on the top of the common reinforced body. The settlement on the top of reinforced body increases with the application of pre-tension. However, the vertical deformation of the reinforced body with single unbonded prestressed reinforcement is smaller under the heaping load. With the increase of pre-tension, the strain of fiberglass geogrid adjacent to prestressed reinforcement decreases and that of fiberglass geogrid at the bottom increases, particularly at the measuring-points near the panel. The pre-tension of the unbonded prestressed reinforcement remains unchanged during applying the heaping load on the top, and increases slightly after completing the heaping load.