Experimentaland Applied Research On Eccentric Composite Foundation With Spiralanchor

Nowadays,the country’s application of transmission line foundations is more and more extensive,and ordinary foundation forms cannot meet the complex topographic requirements of some areas of our country,so a large number of new composite foundations have emerged.This paper proposes a new type of composite foundation—eccentric composite foundation with spiral anchors.This basic type is suitable for soft soil and other foundations,which increases the selectivity for the selection of the basic type of transmission lines in complex geological areas.Based on the theoretical analysis of the new composite foundation,this paper has determined the specific theoretical formula suitable for this foundation type.The calculation theory provided can meet the basic design requirements of the corresponding tower position of the transmission line.In this paper,by means of in-situ tests,the coefficients of the bearing capacity of the upper slab foundation and the lower screw anchor foundation of the foundation are obtained respectively.The full text takes the bearing capacity exertion degree coefficient as the core,and conducts a series of related researches in the field of in-situ test research,soil pressure test and its bearing capacity transmission mechanism.This article mainly completed the following tasks:(1)The eccentric composite foundation with spiral anchors is fully theoretically analyzed,including the analysis of the force characteristics of the composite foundation,and through comparison,the purpose and advantages of the eccentric foundation are explained.The calculation research of the eccentric composite foundation is carried out,and the specific theoretical calculation formula suitable for the stability calculation of the eccentric composite foundation is determined.(2)Using on-site in-situ test as a means,combined with the specifications,the uplift bearing capacity,down-compression ultimate bearing capacity and horizontal ultimate bearing capacity of the foundation are obtained,and the calculation of the foundation design method is correct.Finally,the bearing capacity of the upper slab foundation and the lower screw anchor foundation of the composite foundation is obtained,which provides basic data for the relevant design.(3)The similarity comparison between the numerical analysis and the experimentally measured curve verifies that the numerical model established in this study based on the measured parameters of the soil is reasonable.And through the ABAQUS finite element simulation analysis,the load failure mechanism of the single anchor foundation and composite foundation of different anchor pieces is studied,and the failure mode of the upper slab-column foundation and the lower spiral anchor foundation at the limit failure is obtained,and the transfer of its bearing capacity is obtained.Mechanism analysis provides reference.(4)In the performance study of the eccentric foundation,the economy of the eccentric composite foundation,the anti-corrosion measures of the lower spiral anchor foundation and some main construction methods of the composite foundation are mainly studied,and the Chinese and American standards for anchors are compared.Similarities and differences in foundation bearing capacity.