冲孔灌注嵌岩桩在洋山石油储运一期工程中的应用

Application of Punched Rock-socketed Piles in First Stage of Yangshan Oil Storage and Transportation Project

洋山石油储运一期工程处于孤岛,气象、水动力条件差,土层复杂。工程采用800mm冲孔灌注嵌岩桩,介绍了嵌岩成孔、检孔器检孔、终孔标准、清孔工艺及钢筋笼和混凝土施工技术。指出孔底为大块石时应采用高锤重击;孔底为海泥层时采用低锤轻击;孔底为斜岩面时采用低锤轻击并回填部分块石,必要时调整泥浆密度等特殊情况下的处理办法。经检测,494根冲孔灌注嵌岩桩成桩质量稳定、可靠,能够满足正常连续施工及设计和规范要求。

First stage of Yangshan Oil Storage and Transportation project locates in an isolated island which has bad weather and water dynamic conditions and complicated soil layers. Punched reck-secketed piles with 800mm diameter are used in the project. Some construction technologies are introduced, such as forming holes with reck-socketed method, checking holes with hole detector, finishing holes according to standards, cleaning holes technology as well as construction technology of steel reinforcement cage and concrete. Some treatment methods under special cases are proposed, such as heavily punching soil with high lifted hammer when there are large rocks in hole, lightly punching soil with low lifted hammer when there is sea mud in hole, lightly punching soil with lowly lifted hammer and filling with rocks partly if the hole bottom rock surface is oblique, as well as adjusting mud density when necessary. According to testing results, quality of all 494 piles is stable and credible, which can satisfy requirements of continuous construction, design and code.