(南京长江都市建筑设计股份有限公司， 南京 210002)

［摘要］介绍了昆山鑫宇佳苑项目地下部分主体结构设计，利用已建的结构构件，如桩基、承台底板、地下室外墙等，实现了地下部分结构的融合设计。具体地，已建结构的部分桩基被直接利用，与新打桩一起通过变刚度调平共同承担全部荷载；已建结构的承台底板，部分为直接利用，部分为改造利用（叠合筏板）；已建结构的全部地下室外墙被直接利用，在地下部分施工时被用于基坑围护，在地下部分施工完成时被用作新地下室的外墙。此外，还介绍了新建与已建结构相融合的改建项目所涉及到的地堪补勘和二次基坑支护等关键技术。通过详细的结构计算分析，有效的结构构造措施，新建结构构件与被利用的已建结构构件融为一体，共同参与结构受力。结果表明，基于新建结构与已建结构在建筑体型、具体尺寸和受力特征上存在相同之处，结构设计中可适当利用已建结构构件，实现新建与已建结构的融合设计。 

［关键词］新建结构；已建结构；融合设计；叠合筏板；地勘补勘；二次基坑支护

中图分类号：TU978 文献标识码：A文章编号：1002-848X(2021)15-0044-07

Integration design of new and existing underground structures of Xinyujiayuan project in Kunshan

CHEN  Dahao,  LU  Junheng,  WEI  Daping,  SONG  Shiwei,  XU  Zhun 

(Nanjing Changjiang Urban Architectural Design Co., Ltd., Nanjing 210002， China) 

Abstract:The main structure design of the underground part of Xinyujiayuan project in Kunshan was introduced. The integration design of the underground part of the structure was realized by using the existing structural components, such as pile foundation, bearing platform, basement wall, etc. Specifically, part of the pile foundation of the existing structure was directly used to bear all the load together with the new pile through variable stiffness leveling; some of the used bearing platform bottom plates of the existing structures were directly used and some of them were transformed (composite raft); all the basement external walls of the existing structure had been directly used, which were used for foundation pit support during construction and were used as the external wall of the new basement after construction. In addition, the key technologies of supplementary geology exploration and secondary foundation pit support involved in the reconstruction project of the integration of new and existing structures was introduced. Through detailed structural analysis, calculation and effective structural construction measures, new structural components and used existing structural components were integrated to participate in structural stress. The results show that, based on the similarities between the new structure and the existing structure in building shape, specific size and mechanic characteristic, the integration design of the new structure and the existing structure can be realized by properly using the existing structural components in the structural design. 

Keywords:new structure； existing structure； integration design； composite raft; supplementary geology exploration; secondary foundation pit support

作者简介：陈大好，硕士，正高级工程师，一级注册结构工程师，Email：d.h.chen@163.com。