Numerical Analysis And Field Measurement Of Composite Soil Nailing

There are more and more deep-excavated foundation engineering with development of national economy. Pile-anchor composite soil nailing system which takes over many advantages of both and remedies a number of defects of soil nailing system, has been made widely application in deep-excavated retaining engineering. Although some studies which acquire some theories have been carried out , knowledge of bearing mechanism and working mechanism is still not very clear, design of the system and theoretical system is imperfect. Systemic research on it may enlarge the range of application, save project investment and reduce project accidents. Both social and economic benefits will be achieved.In this article, geotechnical engineering numerical analysis program FLAC4.0 is used, working mechanism and main influential factor of composite soil nailing system with step excavation was calculated in detailed, contain distribution and influential factors of axial force and the max axial force in soil nails; the variation of axial force in anchors; the variation and influential factor of foundation pit horizontal displacement , ground surface settlement, ground surface horizontal displacement and rebound deformation. Secondly, compared with specification JGJ 120-99, the problem of method which be using was pointed out base on a great number of numerical simulation, the interaction between pile-anchor supporting and soil nailing was analyzed. Thirdly, the bearing mechanism of composite soil nailing system was studies by field monitoring, pointed the difference between composite soil nailing system and soil nailing system, discussed the bearing mechanism of supporting structures, compared the result of monitoring with the prediction of numerical simulation, summarized the experiences and lessons from field monitoring.The principal conclusions include: there is interaction between pile-anchor supporting and soil nailing, soil nailing will make a thrust to the pile top, the change of pile-anchor's parameters will influence the axial force of soil nails; The potential...