| In resent years,the frame supporting structure with pre-stressed anchor is a new kind of supporting structure used widely in reinforced slope,however,its design calculation theory is not perfect and there are many problems when designing and computing the structure,there is no corresponding code to be followed in china too,the phenomenon of design theory laging in the practical application appeared. Aiming at existent problems in design calculation of the frame supporting structure with pre-stressed anchor,the design and analysis of the frame supporting structure with pre-stressed anchor are studied mainly in this paper.Firstely,according to the basic principles of finite element method and the existing technology ragulations of building foundation supporting(JGJ120-99),the finite element calculation model of frame structurer is constructed under soil pressure,which consider the bending and torsion deformation of erect column and cross beam.Using MATLAB language,the finite element procedures is compiled too.Associating the engineering case,the mechanic characteristics of frame structure and the influence of internal forces of it by torsion and columns spacing are analysized too,in addition,the calculation parameters of the unit division and the internal forces of anchor are amended for the inversion beam method.Secondly,based on above analysis,the displacement controled design method of frame supporting structure with pre-stressed anchor is researched according to many practical engineering experience,which include following aspects: (1)The design calculation is divided into excavation and work stages in term of construction, process and mechanic characteristics ,a new computing method,lateral displacement controled design method,is put forward,which may ensure the pre-stress reasonably;(2)The frame structure is divided into erect columns and cross beams,considering the interaction of soil-structure and the contribution of pre-stress for controlling displacement of supporting structure ,a simplified structure mechnical model, based on the elastic foundation beam pole method,is constructed,the method is simple and may calculate the displacement of structure.(3)Considering the pre-stress,the method,searching the most dangerous slip surface by computer,has been used to check the stability of the structure. Tthe calculation process of the method is illustrated further with an engineering case.Finally,associating the large scale model test,the design method in the paper is verified. The theory calculated results were compared with experimental results,which show that the design analysis method described in the paper is feasible and rational. |
