海口双子塔-南塔结构设计关键技术研究

海口双子塔-南塔项目位于海南省海口市，为8度0.30g设防烈度地区在建的超高层建筑，建筑高度为428m，结构屋面高度为402.8m。结构采用了空间双向倾斜的巨柱、折线形布置的腰桁架、外凸的巨型支撑和复杂转换结构等形式。对于结构设计中的关键问题，进行了风洞试验、模拟地震振动台试验、关键构件及复杂节点试验和多种分析方法的研究，证实在高烈度、高风压地区采用巨型支撑框架-核心筒-伸臂桁架结构体系是可行的，保证了结构的安全性和经济性。振动台试验结果表明，设置巨型斜撑的外框在地震作用下刚度退化小，具有较好的抗震性能。对于复杂空间布置的外框结构，楼板刚度及传力机制对结构体系影响较大，需要考虑多种情况进行包络分析设计。针对场地条件和上部结构特点，采用了变刚度调平设计方法及大长径比的桩基，通过上部结构-桩-土共同分析保证了结构的安全性和经济性。

Research on key aspects of structural design of Haikou Twin Towers-South Tower

Haikou Twin Towers-South Tower, which is located in Haikou, Hainan Province, is a skyscraper (under construction) in the region of 8-degree（0.3g）of seismic precautionary intensity. The total height of the building is 428 m, and the structural roof is 402.8 m high. Spacial bidirectional twisted mega-columns, fold-line belt-truss, external convex mega-brace and complex transfer structure were innovatively applied to the structure. Various engineering measures, including wind-tunnel tests, earthquake-simulating shaking table tests, key member and joint tests, were conducted. It is proved that it is feasible to adopt mega frame braced-concrete core tube-outrigger truss structure system in areas with high intensity and high wind pressure which ensures the safety and economy of the structure. The shaking table test results show that the outer frame with mega braces has small stiffness degradation and good seismic performance under earthquake. For the outer frame structure with complex spatial layout, the floor stiffness and force transfer mechanism have a great impact on the structural system , and many situations need to be considered. The variable rigidity design method for balance settlement and piles with large length-diameter ratios were adopted in the foundation design based on the soil characteristics and the form of upper structure. Through the analysis of structure-pile-soil interaction，the safety and economy of the structure are ensured.