Study On Application Of High Pressure Rotary Jet Anchoring Cable Technology In Alluvial Formation Of The Lower Yellow River

High pressure rotary jet cable is a new anchoring technology developed in recent years.Compared with the ordinary anchor cable,the rotary jet anchor cable has its relative advantages of high bearing capacity,large anchoring force per unit length,suitable for a wider soil layer,and easier to ensure quality during construction.In this paper,based on the first phase of Huanghe Road project in Jinan starting area,the high pressure rotary jet anchor cable is studied through soil test,field test,theoretical calculation and numerical simulation.The main research contents of this paper are as follows:(1)By collecting alluvial soil samples from the lower reaches of the Yellow River at the construction site,the indoor physical and mechanical properties of typical soil layers at the site are tested and studied,and the basic mechanical parameters of the constitutive model of alluvial soil at the lower reaches of the Yellow River at the site are obtained and evaluated.(2)The construction technology and characteristics of high-pressure rotary jet anchor cable are studied,and the field pulling test of high-pressure rotary jet anchor cable is carried out to obtain the load transfer mechanism and failure evolution law of high-pressure rotary jet anchor cable,which provides a basis for the establishment of mechanical transfer model of highpressure rotary jet anchor cable.(3)A theoretical calculation model of the carrying capacity performance of a single highpressure rotary jet anchor cable during the whole drawing process was established,and a comparative analysis and verification was carried out.A calculation method of the ultimate carrying capacity of a rotary jet anchor cable was proposed,and its rationality was verified through comparative analysis.(4)Based on the modified Cambridge constitutive model,the numerical calculation of high-pressure rotary jet anchor cable support excavation for deep foundation pit was carried out,and the effectiveness of the model calculation was verified by comparing with the monitoring results.The stress and deformation of the high-pressure rotary jet cable support system at different excavation stages were analyzed,and the parameters of the anchoring section of the rotary jet cable were compared and optimized.The stability of foundation pit can be further improved by using high pressure rotary jet anchor cable.