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将框架梁视为刚性梁,从而将锚索集中力转化为加在坡面上的矩形分布力,根据类土质边坡的工程特性,将边坡土体视为弹性体,推导了框架预应力锚索作用下坡体内任一点的预应力传递系数计算方法,得出了锚固预应力自坡面向坡体内的传递规律,并以G323改造工程某实际边坡为原型进行了离心模型试验,得出了预应力在坡体内不同位置处引起的土压力变化,间接得出预应力自坡面向坡体内的传递规律,离心模型试验得出的预应力传递规律与理论推导得出规律基本吻合。研究表明,在分布力作用下,类土质边坡岩土体的塑性形变相对于集中力作用时减小很多,坡体更多表现为弹性体,预应力分布系数受预应力大小的影响减小。相对于无框架单锚,框架预应力锚索措施中,锚索引起的高压应力得以很好的分散,压力分布系数由0.90左右降到了0.40左右,压应力集中程度减小约56%,从而在很大程度上减小了边坡浅层土体的压缩变形,减少了预应力损失,有效地提高了锚固效果,锚间距可由单锚的3.2 m增大为4.2 m左右。
Considering the frame beam as a rigid beam, the concentrated force of the anchor cable is converted into the rectangular distribution force applied to the slope. According to the engineering characteristics of the soil-like slope, the slope soil is regarded as the elastic body, and the prestressing force The method of calculating the prestress transfer coefficient at any point in the downhill body by the anchor cable is deduced. The transfer law of the anchorage prestress from the slope to the slope body is obtained. The centrifugal model test is carried out based on an actual slope of the G323 reconstruction project. The change of soil pressure caused by the prestress at different positions in the slope indirectly leads to the transfer law of the prestress from the slope to the slope body. The law of the prestress transmission derived from the centrifugal model test is in good agreement with the theoretical deduction. The results show that under the action of distributed force, the plastic deformation of geotechnical slope-like rock mass decreases a lot compared with that of concentrated force, the slope body behaves more elastic body and the prestress distribution coefficient is less affected by the prestressing force . Compared with the single frame without frame, the prestressed anchor measures in the framework of the anchor cable caused by high pressure stress can be well dispersed, the pressure distribution coefficient decreased from about 0.90 to about 0.40, compressive stress concentration decreased by about 56% The compression deformation of the shallow soil in the slope is greatly reduced, the prestress loss is reduced and the anchoring effect is effectively improved. The anchorage distance can be increased from 3.2 m to 3.2 m with the single anchor.