某既有建筑地下室增加层高地基基础侧向托换加固工程

Lateral Underpinning of Soil and Foundation in Increasing Storey Height of Basement of an Existing Building

某建造于20世纪20年代的既有建筑加固改造工程,通过增加基础埋深的方式增加原有的1层地下室(局部)的层高。相对原基础埋深,加固改造后的基础埋深需要增加0.45m^1.4m。既有建筑现使用状况良好,地基基础加固设计方案应以保持原地基基础受力及变形状态为原则。结合既有建筑保护要求,采用微型桩对既有地基基础进行侧向托换加固,该托换结构按能够有效限制施工中地基基础的侧向变形、保持原地基承载力进行设计。实施效果和施工监测表明,采用的地基基础侧向托换加固方案安全、可靠,保证了地下室增加层高施工过程中既有建筑的安全。

In one reinforcement and renovation project of an existing building,which was constructed in the 20s＇ of 20 th century,the storey height of original basement（ local） needs to be increased through increasing embedded depth of the foundation. Relative to original value,the embedded depth of foundation after improvement needs to increase 0. 45 m ~ 1. 4m. The existing building is used in good condition,and the foundation reinforcement design scheme should be based on the principle of maintaining the basic stress and deformation state. In combination with the requirements of building protection,the micro pipe piles are used for lateral underpinning of soil and foundation of the existing building. The underpinning structure should be designed to effectively limit the lateral deformation and maintain the bearing capacity of the foundation in the process of excavation. Program implementation effect and construction monitoring show that the lateral underpinning reinforcement scheme is safe and reliable,and it can ensure the safety of existing buildings in the process of increasing the storey height of the basement.