Theoretical analysis and model test study of slope horizontal displacement of grillage flexible supporting structure with prestressed anchors

Based on the influence of excavation process, the free segment of anchor is regarded as spring, and the grillage flexible supporting structure with prestressed anchors is simplified as a vertical continuous beam, in which the bottom is regarded as hinge and the upper part is supported by anchor springs located at different positions. Then, a simplified calculating method of the horizontal displacement of slope of this kind of supporting structure is proposed. The calculating model and sketch are given out, and the relative parameters are determined. Taking a foundation pit for example, the calculation results and analysis of the horizontal displacement of slope show that the middle-top horizontal displacements of foundation pit are larger, and grillage flexible supporting structure with prestressed anchors has obvious effect on strictly controlling the horizontal displacement of foundation pit. In addition, in order to deeply understand the working performance of grillage flexible supporting structure with prestressed anchors, the laboratory model test is carried out based on geometric similarity rule. The comparison of the measured results of displacements and the theoretical calculated results indicates that the general trend agrees well, but there are large difference between the two values, and the model test justly obtains the distribution law of horizontal displacement and the anchorage effect of prestressed anchors. The calculation method of the horizontal displacement of slope is a simplified and approximate method, in which all the calculated parameters are easily determined, so the method is operable and feasible in the initial estimation of the horizontal displacement of slope.