混凝土自复位墙结构地震全过程损伤分析

Seismic damage analysis of self-centering concrete wall structure during earthquake

后张法预应力混凝土自复位墙是一种有效的可恢复功能结构。虽然自复位墙自身在地震中损伤较小,但其与周边构件的变形不协调可使结构损伤严重。为控制结构层面的损伤,设计了1个框架-自复位墙结构,对自复位墙底、梁柱节点、墙梁节点、墙-基础连接、柱-基础连接以及墙-板连接开展损伤控制设计,并对设计的结构进行足尺振动台试验。结构共经历了39次不同设计工况下不同烈度的地震激励,峰值加速度最大达1.0g,位移角最大达3.3%。对结构在历次地震作用下整体、局部构件和节点的损伤发展进行全过程定量分析,结果表明:自复位墙-开槽梁结构在地震作用下的损伤能够得到有效控制,其中多遇、设防地震作用下结构基本无损伤,罕遇地震作用下墙底损伤仅限角部剥落且面积仅为400 cm2,楼板有开裂且裂缝最大仅为1.2 mm,梁端剥落可忽略;自复位墙-开槽梁结构可使整个结构在不同设计位移角下实现多遇、设防地震不坏,罕遇地震小修甚至不修的抗震性能目标;设计的连接方式解决了结构中构件之间的变形不协调问题,提高了自复位墙结构层面的可修复性。

Post-tensioned self-centering concrete walls are well-developed resilient structures.Prior structure-level tests indicate components around the self-centering walls could experience severe damage due to the displacement incompatibility.A self-centering wall-frame building was designed with explicit control of the structure-level damage by considering the low-damage detailing of wall base,wall-to-floor connection,wall/column-to-foundation connection and beam-column/wall joints.A shaking table test was conducted on the designed building at full-scale to verify its structure-level response and resilience.The buildings with different configurations and design drifts were subjected to 39 tests with a range of intensity ground motions.A maximum peak ground acceleration of 1.0g and a maximum drift of 3.3%were observed during the test.The damage progression of the whole structure,including local components,connections and joints were recorded and analyzed quantitatively.Results show that the structural damage under earthquake can be effectively controlled,the structure does not have obvious damage during frequent earthquake and fortified earthquake.Damage during rare earthquake is concentrated at wall toe with maximum spalling area of 400 cm2,floors with maximum crack of 1.2 mm and beam ends with no obvious spalling.It is concluded that a combination of self-centering walls and slotted beams can form an excellent low-damage structure and achieve the performance objectives of no damage for frequent and fortified earthquakes and immediate occupancy following rare earthquakes.The connections designed can successfully address the displacement incompatibility issues and improve the structure level resilience significantly.