以石灰岩作为天然地基的筏板基础在超高层建筑中的应用

Application of raft foundation with limestone as natural foundation in super high-rise building

随着武汉地区城市化进程的不断加快,岩溶发育区的超高层建筑也随之日益增多,如何选择经济合理的基础形式成为一道难题。以洪山村城中村开发改造用地K2地块(诚功大厦)为例,在武汉地区提出超高层建筑(大于200m)可采用以石灰岩为天然地基的筏板基础,经专项论证,该基础形式可行。对主楼进行补充勘察,在主楼基础范围内按3.0m×3.0m方格网间距布置勘探孔;同时以补充勘探孔兼做注浆孔,对基础底面以下一定深度范围内石灰岩中岩溶洞隙进行注浆处理。针对岩溶注浆效果分别进行了现场施工监测、钻孔取芯检测和注水试验检测,结果显示岩溶注浆加固效果良好,满足设计要求。根据沉降观测报告可知,现阶段累计沉降较小、沉降速率较缓、整体沉降均匀,属正常荷载沉降。

With the continuous acceleration of urbanization in Wuhan area,the number of super high-rise buildings in karst development areas is increasing day by day.How to choose an economic and reasonable basic type has become a difficult problem.Taking plot K2(Chenggong Mansion)of the development and renovation land for villages in Hongshan village as an example,it is proposed that a raft foundation with limestone as natural foundation can be used for super high-rise buildings(more than 200 m)in Wuhan area.After special demonstration,the foundation type is feasible.Supplementary investigation was conducted on the main building,and exploration holes were arranged within the foundation range of the main building according to 3.0 m×3.0 m grid spacing.At the same time,the supplementary exploration hole is also used as the grouting hole to carry out grouting treatment on the rock cave gaps in limestone within a certain depth range below the foundation bottom surface.According to the effect of karst grouting,the site construction monitoring,drilling coring test and water injection test were carried out respectively.The results show that the reinforcement effect of karst grouting is good and meets the design requirements.According to the settlement observation report,at present,the accumulated settlement is small,the settlement rate is slow and the overall settlement is uniform,which belongs to normal load settlement.