超深孔压静力触探在工程勘察的应用

Application of Super-deep Piezocone Penetration Tests in Engineering Investigation

研究目的:依托孟加拉国帕德玛公铁两用大桥工程勘察项目,引进国外先进静探设备,探寻进行深孔静力触探的途径,实现我国静力触探测试技术的突破。在实际工程中通过技术改进不断完善与发展深孔静力触探技术,以提高工程勘察效率、质量,节约成本、创造效益。研究结论:(1)运用多重套管工法能克服探杆侧壁摩擦力过大和静探测试无法穿越砾石、卵石夹层的难题,使陆地静力触探测试深度突破100 m;(2)与地质钻探进行比较,深孔静力触探技术在数据可靠性、时效性和经济性方面具有明显优势;(3)通过技术对比得出,深孔静探测试与标准贯入测试有较好的深度拟合性;(4)在软土、砂土地区的工程勘察中,该技术日趋完善,测试效果好,值得在类似地质条件地区推广应用;(5)该技术在水上或近海进行地质勘察尚需要进一步研究。

Research purposes： Relying on the engineering investigation project of Bangladesh Padma multifunctional bridge, we introduced the foreign advanced piezocone penetration test（PCPT）equipment, and sought for the best way of deeper PCPF tests. The deep PCPT test technology was developed and improved in the practical engineering through technology improvement, to increase the efficiency, quality and drop cost, create beneficial result. Research conclusions： （ 1 ） Apply the multiple - casing method to conquer the problem of great friction force of side wall of poles and that the PCPT test unable to penetrate the gravel and pebble interlayer. The PCPT test depth on land area finally went down to more than 100 m. （2） Compared with the geological drilling, the deep PCPT technology has obvious advantages in the aspects of data reliability, timeliness and economical efficiency. （3） As technical view,it is obvious that the super- deep PCPT test and standard penetration test （SPT） have good depth fitting degree. （4） In the engineering investigation on soft soil and sandy area, the technology became increasingly reliable so that it was deserved the popularization and application in similar area. （5） The technology needs to be further studied for the geological survey on the water or offshore regions.