岩溶区灌注桩施工常出现塌孔、漏浆、涌水等，尤其是直径较大的灌注桩。为解决岩溶区地铁车辆段大直径灌注桩施工技术难题，以深圳岩溶区某地铁车辆段桩基施工为例，研究岩溶区地铁车辆段大直径灌注桩施工技术，探讨不同尺寸溶洞处理的施工方法，分析岩溶区大直径桩基施工效果。结果表明，溶洞为无填充或半填充状态时，溶洞高度不大于1.0m时，采用注浆法处理，溶洞高度为1.0~5.0m时，采用充填法处理；溶洞为全填充状态时，溶洞高度不小于1.0m时，采用注浆法处理；溶洞高度不小于5.0m时，采用全套管成孔工艺施工灌注桩；桩身混凝土芯样抗压强度值为40.8~59.1MPa；岩溶区桩基施工完成后，Ⅰ类桩占比为97.28%，Ⅱ类桩占比为2.72%。

The construction of cast-in-place piles in karst areas often faces difficulties such as collapse, slurry leakage, and water inrush, especially for larger diameter piles. To solve the technical problems in construction of large-diameter cast-in-place piles in subway vehicle depots in karst areas, taking the pile foundation construction of a subway vehicle depot in Shenzhen karst area as an example, the construction technology of large-diameter cast-in-place piles in subway vehicle depots in karst areas is studied, and the construction methods for treating karst caves of different sizes are discussed. The construction effect of large-diameter pile foundations in karst areas is analyzed. The results show that when the karst cave is in an unfilled or semi filled state and the height of the cave is not greater than 1.0m, grouting method is used for treatment, and when the height of the cave is 1.0~5.0m, filling method is used for treatment. When thekarst cave is in a fully filled state and the height of the cave is not less than 1.0m, grouting method is used for treatment, and when the height of the karst cave is not less than 5.0m, the full casing drilling process is used to construct the cast-in-place pile. The compressive strength of concrete core sample of the pile body is 40.8~59.1MPa. After the completion of pile foundation construction in karst areas, the proportion of Class I piles is 97.28%, and the proportion of Class II piles is 2.72%.

TU753

中铁十六局集团有限公司技术开发项目（202128777）