Analysis And Design Cast Grid Of The Total Portfolio

The combination grid is a space grid structure, and its upper part is a concrete floor, and its bottom chord and webs is circular steel composition. The kind of structural give full play to the strength of the steel and concrete, with stiffness, and high load capacity. Existing norms and existing engineering applications mainly based on a combination of pre-cast concrete panels assembled grid, and the seismic performance of this structure is deficiencies. To solve this problem, a combination of grid winding full-cast concrete floors can be the way, but there is a lack of a reasonable cross-section design features consistent with its force, and its design can only rely on engineering experience and conservative theory. In view of this, we carried on the thorough analysis to the whole cast-in-situ composite space truss rib plate mechanical characteristics using the finite element method, and combining with an engineering field data and discussed the method of design.Through on-site testing to the winding concrete floors and bars of a combination grid of practical engineering, initially grasped the stress distribution in the concrete floors and internal force distribution of rods. While analysing the combination grid for finite element, Comparative analysis of the finite element simulation results with field test results to verify the reliability of the finite element method. Combined numerical example discusses several combinations of mesh grid, high-span ratio, aspect ratio, high beam cross-rib ratio, wide-span ratio, concrete panels and ribbed reinforcement ratio and other factors on a combination of network structure force and deformation effects. Field measurement and theoretical analysis shows that the overall performance of the whole cast good combination grid, winding concrete is in compression ribs, the stress is more evenly distributed, can give full play to the advantages of concrete material strength.Due to the existing calculation method of the combination grid is more complex, not easy to engineers, the lack of practical value, this paper presents a simplified calculation method of the combination grid. Regression analyzed the relationship between affecting the main grid in combination with a combination of sensitive parameters of the mechanical properties of each truss member forces, and proposed a simplified internal force formula of the composite space truss string concrete floor, webs and bottom chord, and gived the simplified formula of the whole structure deflection, and provided convenience for engineering design.