Stress Analysis Of Curved Steel Vice Grid Of Hong Kong-Zhuhai-Macao Bridge

The foundation pit project of eastern and western artificial island of HongKong-Zhuhai-Macao Bridge adopts the structure of large diameter steel cylinder, using twocurved steel plate vice grid to connect two adjacent steel cylinders. This structure has thecharacteristics of simple to construct, high efficiency, fewer steps, and you can make curvedsteel plates in factory and then transport them to the construction site as a whole, makingthe difficulty of construction and costs of material significantly reduced. The cofferdam andisland wall have a good sealing performance and a good stability.Firstly this paper studies three classical earth pressure theories which can be used in thestress analysis of a curved steel lattice structure, and then we do a test on land throughwhich we analyze the static stress of curved steel vice grid in different conditions. We drawthe conclusion as follows, after the vice grid is vibrated-sink, the stress of tongue andgroove, vice grid is not yielded. While it is filled with water and sand, the stress of somepoints is too much large. Secondly, according to the design data and the actual workingconditions, we adopt the finite element method to analyze the structure of vice grid indifferent depths. From the result, we know that vice grid is not yielded on three differentheights and the wide tongue and groove is a large part of the force in the whole structure.According to the test results and the analyzed results with finite element method, wepropose the optimized design of the vice grid as follows, when the height of the waterinside vice grid bin exceeds a certain value, we can place more transverse ribs to increasethe stiffness of tongue and groove. Under the high water head, the location where steel pipepiles weld tongue and groove may be stress concentration. So it is recommended that thelongitudinal stiffeners should be placed on the location to improve stress distribution. Third,in actual conditions the water level of vice compartments should be reasonably controlled,and the monitoring of strain and stress should be strengthened. To ensure the structure safeand reliable, when the height of curved steel vice grid is changed, we may place moresniffers properly on tongue and groove.