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空心板楼盖受力特性及受力岛设计方法 I：岛状受力特性及等代梁法的局限性 谢靖中 (上海交通大学土木工程系，上海 200030) 　　摘　要　本文第I部分分析了板式楼盖结构与梁式楼盖结构受力差异，表明板式楼盖呈现岛状受力特性，即内力向柱端岛状区域内集中，而其它部位相对较小。空心板楼盖仍呈现板式楼盖的受力特点，并且岛状受力特性更明显，内力更集中于柱端区域。分析表明，等代梁法的计算效果与梁格的疏密程度有关，网格越密时越接近板式楼盖的实际状况，反之则差别很大。等代梁法使结构侧向刚度大于实际值。扭转刚度的折减对等代梁计算结果影响显著，合理地确定折减幅度是等代梁法的难点。本文第I部分得出的板式楼盖受力特性是受力岛设计方法的基础。 　　关键词　板式楼盖，空心板楼盖，等代梁，受力特性，扭转刚度 The characteristic and insular design method of hollow slab-column Structures I：The insular characteristic and the shortage of the equivalent cross-beam method Xie Jing-zhong(Depart. of civil engineering, Jiaotong Univ. of Shanghai, Shanghai 200030) Abstract: The differences between slab-column structure and beam-column structure are analyzed in Part I of the paper. It is illuminated that slab-column structure behaves insular character, in which the inner forces is concentrated on the insular zone around the column. The characteristic of hollow slab-column structure is similar to that of the common slab-column structure, with more explicit insular character and the more concentrated inner force. It’s also illuminated that the results of equivalent cross beam is affected by the density of beam grid, the more beam grid leads to better result, or leads to rough result.And the lateral stiffness obtained by equivalent cross beam is larger than reality. The decreasing ratio of torsional stiffness heavily influences the results of equivalent cross beam method, and it’s difficult to determine exact value of the ratio for practical usage. The characteristic obtained in Part I is the fundament of insular design method.Key words: slab-column structure, hollow slab-column structure, equivalent cross beam, structural characteristic, torsional stiffnes 1 引 言 　　板式楼盖结构是很早就有的一种建筑结构类型，如带柱帽的无梁楼盖结构、预应力大板结构、升板结构等。这些板式楼盖结构由于自重较大、或者施工工艺复杂，多在一些特殊结构中应用，未能大范围推广。空心板楼盖结构是我国今年来发展起来的一种新型板式楼盖结构[1]。空心板楼盖结构利用空腔板良好的力学性能，有效降低结构层高，并且钢筋帮扎简单、支模简便、施工速度快，经济技术优势非常明显。空心板结构克服了早期板式楼盖结构的自重大、施工工艺复杂的缺陷，具有大范围推广的潜力。能适用于大跨、大开间的公共建筑、高层商业建筑，替换原有的梁板式楼盖结构。在众多厂家和研究单位的努力下，空心板结