张丽丽 张国锋

内容摘要：在对白居寺进行现场工程地质勘查、地质雷达探测的基础上，得出了白居塔建筑形制和建筑结构特点，整个塔体位于高强度板岩为主的宗山山体上，承载力满足上部荷载需要。采用MIDAS GTS数值仿真软件，分析了自重荷载和地震作用下不同基岩高度的塔体的稳定性，模拟结果表明：（1）较高山体模型结构最大变位以6层墙体斜向下变位为主，较低山体模型整体结构变位以向中心的水平变位为主，自重作用下较高山体模型安全稳定系数高于较低山体，但建筑地基承载力均没问题。（2）在7度多遇地震作用下，两个模型整体结构的抗震稳定性较好，墙体最大剪切应变带出现在7层平台对应的内墙体下部；在8度多遇地震作用下，较高山体模型主体结构基本处于安全状态，较低山体模型主体结构不满足安全要求。

关键词：白居塔；地震响应；数值模拟；稳定性分析；保护加固

中图分类号：TD85 文献标识码：A 文章编号：1000-4106（2018）05-0128-09

Abstract： Based on field engineering geological exploration and geological radar detection data， the construction form and architectural structure of the Baiju pagoda has now been determined. The pagoda is located on Zongshan Mountain， which is mainly composed of high strength slate， the bearing capacity having been found to be enough to support the upper load of the building. Using MIDAS GTS numerical simulation platform， the stability of the pagoda at different base rock heights under the conditions of its own weight and seismic action was analyzed with the following results：（1）The major maximum structure displacement of the higher mountain model leads to a downwards sloping displacement by six layers of walls， while that of the lower mountain model is horizontal with inward displacement. When computed to account for gravity， the stability of the higher mountain model is found to be higher than that of the lower mountain model， but the bearing capacity of both building foundations is sufficient.（2）When earthquake intensity reaches seven or higher， the seismic stability of the whole structure of the two models is sound， while the maximum shear strain zone of the buildings wall appears in the lower part of the inner walls， which corresponds to the 7th platform of the pagoda. When earthquake intensity is eight or higher， the framework of the higher mountain model remains basically safe， while that of the lower one fails to meet safety requirements.

Keywords： Baiju pagoda； seismic response； numerical simulations； stability analysis； reinforcement

1 引 言

目前古塔建筑保護是文物领域重点研究方向，该研究领域主要集中在对古塔本体结构、材料风化、破坏、修复加固等；而对于建造在斜坡古山体上的古塔建筑，综合考虑斜坡山体地基与古塔在外力荷载下的相互作用及变形力学机制研究很少见报道[1-7]。西藏是我国宗教圣地，大量的古代寺庙塔体建筑在宗教信徒中具有崇高的地位，由于古塔年代久远，多为砖石砌筑、土层粘结结构，风化严重，整体性差，在地震动力作用下易发生严重损坏。……