Cracks Control Of Over-length Basement Concrete Structure Based On Analysis Of Temperature Effects

The temperature effect is the main reason of causing cracks in the over-length concretestructure, so correlative research and analysis have important implications for the anti-leakagecontrolling in the basement. For the boundary conditions of the concrete structure basement,it’s common to regard the basement as consolidated up above the foundation, which makesanalytical value larger than actual value. In this paper, a practical project of over-lengthconcrete structure basement in Guangzhou is studied. In the condition that the whole structureis under the elastic restraint, the temperature effect analysis will be carried out. The maincontents are as follows:(1)This paper introduces the research detail of the temperature field, temperature strain,creep strain and shrinkage problem, while also introduces stress relaxation and the algorithmfor environment temperature difference and the shrinkage temperature difference.(2)This paper analyzes the temperature effect respectively under construction phase andservice phase by using the finite-element software ANSYS. To analyze the temperature effecton pillars, floors and walls in construction phase, the result generally concludes thedeformation characteristic and the force distribution law of the members in the structure.While comparing the different temperature effect between the structure under constructionphase and service phase, it shows that the maximum deformation of the structure appears inthe longitudinal ends. When being away from the axis, the deformation gradually reduces, themaximum force appears in the bottom of column, bending moments and shear are weakened. Stresses concentration appear in junction between side walls and floor, junction between thebottom of side wall and floor, the narrow parts of the top floor, the short side of the hole.(3)By establishing16finite-element models, this paper analyzes and discusses the mainfactors influencing the over-length concrete basement, focusing on the variation of the columncross-section, baseboard thickness, side wall thickness and the horizontal ground resistancecoefficient. The results generally concludes the specific laws that this variety of factors haveon the members of the structure and figures out the influence degree of each factor. Theresults show that column section and horizontal ground resistance coefficient ha ve greatinfluences on the temperature effect of the structure, but effects of floor and side wallthickness are not obvious.(4)Based on the analysis result conducted by the ANSYS, integrating the crack controlrules and current crack-preventing measures, this paper puts forward a series of specificcrack-preventing measures for this specific engineering example on the scale of design,construction and material. All the finished work can serve as referential advice for practicalengineering.