重型设备-桩箱基础-砂卵石地基体系动力稳定性振动台试验  

SHAKING TABLE TESTS FOR DYNAMIC STABILITY OF HEAVY-DUTY EQUIPMENT-PILE BOX FOUNDATION-SAND GRAVEL SOILS SYTEM

作　　者：王志华[1,2] 陈国兴[1,2] 周恩全[1,2] 

机构地区：[1]南京工业大学城市地下空间研究中心,南京210009 [2]南京工业大学交通学院,南京210009

出　　处：《工程力学》2013年第2期196-202,共7页Engineering Mechanics

摘　　要：设计并完成了重型设备．桩箱基础．砂卵石地基体系地震反应的大型振动台模型试验，分析了设备结构位移和转角反应特征以及桩箱基础和砂卵石地基的动力稳定性。试验结果表明：设备结构位移反应峰值呈上大、下小的三角形分布，位移和转角反应受结构振动方向第一振型控制；振动过程中基底两侧土反力增量不均，由上部重型结构水平惯性力引起的基础转动效应明显，这也是基础发生倾斜的主要原因；箱形基础振动对周围地基土产生挤密作用，基础转动显著影响侧墙土压力分布形态；强震作用下，砂卵石地基持力层振动孔压比能达到0．3-0．5，振动孔压的累积和消散可引起基础附加沉降。试验结果可为砂卵石地基箱形基础抗震设计提供参考和借鉴。A heavy-duty equipment-pile box foundation-sand gravel ground model system was designed and then tested on a shaking table. The dynamic displacement feature of the main equipment structure and the dynamic stability of the tested system were analyzed in detail. The test results indicated the structure dynamic displacement with a big-end-up triangle distribution was controlled by the first mode of the structure. In addition, the reaction increments on the two sides of the box foundation base were unbalanced during the vibration. The rotation effects of the box foundation, induced by the horizontal inertia force effects of the superstructure, were remarkable. This was also the major factor resulting in the declivity of a box foundation. The vibration of the box foundation made the surrounding soils compacted. The rotation of the foundation could obviously influence the distribution modality of the soil pressure on the side wall. Additionally, the excess pore water pressure ratio of the tested sanff gravel soils could be reached to 0.3-0.5. The build-up and dissipation of the excess pore water pressure might beget the extra settlement of the box foundation. These conclusions supplied some references for the seismic design of the box foundation in sand-gravel ground.

关 键 词：重型设备 动力稳定性 桩箱基础 砂卵石土 振动台试验 

分 类 号：TU435[建筑科学—岩土工程]