为提高土石坝的安全运行性能,提出在常规土石坝中设置混凝土纵向增强体,这一刚性结构体在坝体内具有防渗、受力和抵抗变形三重作用.采用经典力学方法定量分析了纵向增强体的防渗作用、抗变形能力和承受外力的能力,得出增强体厚度与上下游水位、堆石坝体物料特性之间的定量关系.理论公式推导将增强体作为竖向固端梁,主要受上下游水体作用、堆石主动土压力和因心墙和堆石差异沉降而产生的堆石对墙体两侧的拖曳力作用.由扰曲微分方程得出增强体顶部变位及转角和底部固定端应力计算公式,并以此进行设计复核,进而提出通过兼顾基础灌浆和满足增强体应力要求的预埋灌浆钢管的施工方法.%To improve the operational safety of earth rockfill dam, a longitudinal reinforcement is proposed. This rigid structure has triple functions as the seepage controlling,stress resistance and deformation resistance. Based on the classical mechanics,its anti-seepage effect,anti-deformation ability and the capacity to withstand external force is quantitatively analyzed. In addition, the quantitative relationships between the reinforcement thickness and the downstream water level, as well as the material properties of the rockfill dam are derived. For the theoretical derivation,the reinforced body is regarded as a fixed-end beam, loaded by water pressures from upstream and downstream,the active earth pressure from rockfill and the vertical drag force due to the differential settlement between core walls and rockfill. The top displacement together with the rotation angle and the bottom stress of the fixed end are derived from the deformation differential equation and validated through designing reviews. Subsequently,the construction method of buried steel pipe,which is adopted to perform the base grouting and also to meet the strength requirements, is put forward. The proposed method plays an important guiding role in rehabilitating and reinforcing the dangerous earth rockfill dams, as well as the design and construction of new dams.
展开▼
