气囊式框架地梁边坡支护结构力学性能分析

Mechanical properties of airbag frame ground beams for slope support

针对地震、崩塌等自然灾害频发而导致的边坡失稳问题,提出了可快速应对抢险救灾工作的气囊式锚杆框架地梁新型结构,并阐述了该新型结构的工作机理。分析气囊框架地梁受荷时玻璃钢与气囊的受力特性,给出了气囊框架地梁承载力计算方法;结合气压传动和双层弹性地基梁理论,建立了气囊框架地梁-锚杆-土体协调变形的计算模型,给出了气囊式框架地梁在边坡支护施工阶段与工作阶段的力学效应计算方法。结果表明:①气囊式框架梁结构承载力主要由框架梁板厚、板材强度、气囊内压和高度决定,增加框架板厚、板材强度、气囊内压和高度可以提高结构承载力;②气囊式框架梁支护边坡存在施工和工作两个阶段,工作阶段位于坡脚处的框架梁剪力和弯矩出现较大的上升,设计时应作为最不利因素着重考虑;③支护设计时还应综合考虑支护效果、结构承载力和经济性给出设计方案,确保结构在实际抢险救灾中的可靠性、时效性和经济性。研究成果可在边坡快速支护中为新型结构的设计应用提供理论依据和指导。

In view of the slope instability caused by frequent natural disasters such as earthquakes and collapses,a new type of ground beam structure with airbag anchor frame which can quickly respond to rescue and relief work is proposed,and the working mechanism of the new structure is described.The stress characteristics of FRP and airbag are analyzed when the ground beam of airbag frame is loaded,and the method for the bearing capacity of the ground beam of airbag frame is given.Combined with the theory of pneumatic transmission and double-layer elastic foundation beam,the model for calculating the coordinated deformations of the airbag frame ground beams,bolts and soils is established,and the relevant method for the mechanical effects of the airbag frame ground beams at the construction stage and working stage of slope support is given.The results show that:(1)The bearing capacity of the airbag frame beam structure is mainly determined by the thickness of frame beam,the strength of plate,and the internal pressure and height of the airbag.Increasing the thickness of frame plate,the strength of plate,and the internal pressure and height of airbag can improve the bearing capacity of the structure.(2)The airbag frame beams for slope support have two stages:construction and working.The bending moments and shear forces at the working stage are larger than those at the construction stage,and the shear forces and bending moments of the frame beams at the foot of the slope rise greatly at the working stage,which should be considered as the most unfavorable factor in the design.(3)The support design should also comprehensively consider the support effects,structural bearing capacity and economy,and give the design scheme to ensure the reliability,timeliness and economy of the structure in the actual rescue and disaster relief.The research results may provide a theoretical basis and guidance for the design and application of the new structure in rapid slope support.