地下结构中混凝土结构边界约束效应分析

Boundary Restraint of Concrete Structures During Underground Construction

结构变形受到约束时会在其中引发应力。边界约束是混凝土工程中常见的现象,如新旧混凝土接触面、桩和地基土与基础底板的接触处、贯穿施工缝或诱导缝边界的钢筋等。工程设计考虑这些边界的约束效应才能准确地得出混凝土施工期间或使用条件下变形作用而产生的附加效应。就地下工程中常见的边界约束建立力学简化模型,探讨了边界约束的取值方法。结合工程实例分析边界约束对混凝土结构早龄期性能的影响。

The stress will be generated in structures when their deformations are constrained.The boundary restraints are common phenomena in engineering,such as the interface restraint of young-old concrete,the restraint of soil and pile to the base plate,and the boundary restraint of steel that through the post-cast strip,induction joint and construction strip.As long as these constrains effects are fully considered,the additional effects which caused by the structural deformation during the construction period and service period can be obtained accurately.In full consideration of the usual boundary restraint and the establishment of model of mechanics,methods of arriving at restraint of some common members in underground engineering are brought forward.Finally,through the application of the method in an engineering case,the influence of restraint on the early age concrete is presented.