微型钢管桩不同施工工艺在既有建筑物地基加固工程中的应用与比较  

Application and comparison of different construction technologies of mini steel pipe piles in foundation reinforcement engineering of existing buildings

作　　者：姚智全[1] 曹光栩 吴渤昕[1] Yao Zhiquan;Cao Guangxu;Wu Boxin(CABR Foundation Engineering Co.Ltd,Beijing 100013,China)

机构地区：[1]建研地基基础工程有限责任公司,北京100013

出　　处：《建筑科学》2021年第7期94-99,共6页Building Science

摘　　要：微型钢管桩是既有建筑物地基加固中常用的桩型之一,而锚杆静压成桩与钻孔成桩是实现这一桩型的比较常用的两种被动限沉加固工艺。通过对应用上述两种不同加固工艺的工程实例进行对比分析,得出以下结论:锚杆静压桩加固方案由于属于挤土工艺,单桩承载力发挥充分,见效快,附加拖带沉降增加较小,比较适用于地基土层以软土为主的建筑物地基加固;而钻孔桩加固方案,虽属于被动限沉方法,但也有一部分主动促沉的效果,在倾斜率超过规范允许值不是很大时,可以用来调节差异沉降,特别是与后压浆技术相结合,能更有效地调节地基基础与上部结构的相互作用。钻孔灌注桩加固方法适用范围较广,尤其是可用于地基土层存在较硬土层的工况,但加固初期会加速建筑物沉降发展,引起的附加沉降相对较大,所以建议施工时应严格要求打桩顺序和时间间隔,避免引起更大的土体扰动。在条件许可的情况下,可以把这两种不同施工工艺的微型桩结合起来,充分发挥各自优点,更加有效地对建筑物进行快速加固和变形调节。Mini steel pipe pile is one of the commonly used pile types in foundation reinforcement of existing buildings,and anchor jacked pile and bored pile are two commonly used passive reinforcement technologies to realize this pile type. By comparing and analyzing the engineering examples using above two different reinforcement technologies,the following conclusions are drawn: as anchor jacked pile reinforcement method belongs to soil compaction technology,the bearing capacity of single pile is fully exerted,and it has an earlier effect,causes less additional settlement of the building. This technology is more suitable for the foundation reinforcement of the soft soil mainly in the foundation soil layer. In comparison,bored pile reinforcement,although it belongs to the passive reinforcement technology,also has some effect of actively promoting settlement. When the inclination ratio is not much higher than the allowable value of the code,this technology can be used to adjust the differential settlement.Especially in combination with the pile-end post-grouting technology,it can more effectively regulate the interaction between foundation and superstructure. The bored pile reinforcement technology has a wider range of applications,and it can be used in the condition of the hard soil layer in the foundation soil. But the bored pile reinforcement technology will accelerate the development of building settlement at the initial stage of the reinforcement,and causes a large additional settlement. It is recommended that the piling sequence and time interval should be strictly required during the construction of the bored pile to avoid causing greater soil disturbance. If conditions permit,these two types of mini steel pipes with different construction technologies can be combined to give full play to their respective advantages and more effectively carry out rapid reinforcement and deformation adjustments to buildings.

关 键 词：微型钢管桩 锚杆静压桩 取土钻孔桩 地基加固 

分 类 号：TU443[建筑科学—岩土工程]