荆沙长江公路大桥桥基碎石土力学参数获取方法的探讨

DISCUSSION ON ACQUISITION OF GEOTECHNICAL PARAMETERS OF BRIDGE GROUND OF THE JINGSHA YANGTZE RIVER HIGHWAY BRIDGE

荆沙长江公路大桥全长 4 180m ,其 50 0m跨度的双塔PC斜拉桥处于亚洲第一位。斜拉桥主塔对基础持力层要求很高 ,如何确定近百米厚的河湖相沉积物 ,尤其是碎石土的力学参数是大桥勘查中的一个难点。对超过规范深度要求的碎石土力学参数的获取进行了探讨 ,利用超重型动探连续锥贯、物探测井、现场静压等方法进行对比试验获得了可靠资料 ,认为超重型 (N12 0 )动探在深厚碎石土中获取力学参数是一种行之有效的方法。同时还验证了弹性波动理论用于动探试验是可行的。

The Jingsha Yangtze River highway bridge is a 4180 m long and its double tower bridge with a span of 500 m(the largest in Asia). It is a great difficulty to determine the geotechnical parameters of river and lake phase deposits,especially the detritus soil. This paper discusses the methods of getting the geotechnical parameters. Test shows that the application of elastic wave theory is feasible to cone penetration and that reliable data can be gained by overweight dynamic test,cone penetration,geophysical measure,field static pressure test. It is concluded that overweight cone penetration is an efficient method for getting the geotechnical parameters from the heavy bedded detritus soil.