三桥静力触探在桩基中的应用研究

APPLICATION OF TRIPLE-BRIDGE CONE PENETRATION TEST IN PILE FOUNDATION

通过研发具有强贯入能力的新型步履式静力触探,使之能够对强风化岩等较硬岩土层进行测试,从而满足端承型桩勘察深度的要求,同时在原有双桥静力触探的基础上增加总贯入力的测试,并称之为三桥静力触探。通过三桥静探试验与钢管桩沉桩试验的对比研究,将整个岩土层作为一个系统考虑,提出一套较精确估算指定桩径和深度下的压桩力、或指定压桩力和桩径下桩入土深度的新方法。并通过三桥静探试验与静载荷试验的对比研究,总结出珠三角地区端承型桩极限承载力的估算新方法,填补了目前规范的空白。以上研究成果表明具有强贯入能力的三桥静力触探能够为桩基础的设计、施工和检测提供非常有用的指导。

A new type of static cone penetration which can measure the total penetration force on the basis of the double-tridge cone penetration,called as the triple-tridge cone oenetration,was developed. The device can penetrate hard soil clayers such as strong weathered rock and reaches the exploration depth required by the end bearing pile. It was called the triple-bridge cone penetration with the total penetration force measured on the basis of the double-bridge cone penetration test. An accurate method for estimating the piling pressure with the specified pile diameter and estimating the depth or embedded depth of pile with the specified piling pressure and pile diameter was proposed based on the comparisons between the results from the triple-bridge cone penetration test and the pressure test of model piles. A new method for estimating the limit bearing capacity of the end bearing pile in the pearl river delta region was derived according to the results of the triple-bridge cone penetration test and the static loading test.