The Stress Analysis And Design Research Of The Cast-in-situ Hollow Concrete Floor System

Cast-in-situ reinforced concrete hollow slab floor system is a new floor structuralsystem, which are formed after pouring of concrete according to certain rules ofplacement of embedded fillers. The embedded fillers have a variety of forms, such assolid, hollow cylinder, hollow cavity. The hollow slab floor system has the advantagesof light weight, material saving, noise and hot isolation, large moment of inertia. Thetechnology has great practical value, many scholars carried on a large amount oftheoretical and experimental research, a lot of results have been yielded. This thesisfocuses on the research of the mechanical properties and the design method of the tubefiller hollow slab system. The ANSYS three-dimensional finite element analysis ismainly used to do the research, which is in study of the stiffness, flexural property basedon elasticity theory.In this thesis, according to numerical analysis the job of the following respects aremainly done, which draw the corresponding conclusion.â‘ Use ANSYS to analyze the tube filler hollow slab whose two edges are fixedbearing, study on the whole bending stiffness difference and the influence factors ofthe bending stiffness when the tube fillers are laid in different directions. the thesisgets that the volumetric void ratio is the main reason of the whole bending stiffnessdifferences in two directions. when the volumetric void ratio is large, the bendingstiffness of the tube filler radial direction is about0.9times less than the longitudinaldirection.â‘¡Use the programming function of ANSYS to calculate the bending moment theedge-supported hollow slab, research the differences of the bending properties of thetube filler radial direction and the longitudinal direction, as well as the similarities anddifferences of the bending properties in two directions of the solid slab. the thesis getsthat the edge-supported hollow slab has stress on both directions, the bending propertyof both directions are basically the same with the solid slab, the reinforcement can becalculated according to solid slab elastic analysis.â‘¢Analyze the structural stress property of the column-supported hollow slabunder the vertical load, calculate the bending moment distribution of the slab strip andof the control cross-section along the width direction. the thesis gets that the stress ofthe column-supported hollow slab system are similar on tube fillers both radial and longitudinal directions; the stress distribution of the tube fillers radial directionpresents "undulation" state, the overall trend of which are the same with the tubefillers longitudinal direction which has the same strip span; each side of the columnswithin1/2zone grid slab can be as a whole on the stress analysis, all the loads on thestrip must be calculated, the stress property of the strip are similar with the planeframe beam; the distribution of the bending moment along the strip width direction isthat in the support position the column strip take the most bending moment, in themiddle position the bending moment distribution is much more average.â‘£Research bending moment calculation method of column-supported hollowslab based on PKPM, use PKPM to carry on equivalent method and analogue crossbeam method, compare the bending moment value of this method with the ANSYSentity infinite element analysis bending moment value on programming calculated,evaluate the accuracy of each method on calculating the bending moment of thecolumn-supported hollow slab system.