Special Load Effect Analysis And Design Standardization Of Lattice Shells For Pre-homogenization Storage In Cement Mill

Double-layer lattice shells are often adopted as the roof structures of the pre-homogenization storage in cement mill. Because of the large span and complex loads, the design of the lattice shells is very difficult for common engineers and often need to done repeatedly. Therefore, the standardization of the design of the lattice shells will improve not only the safety of structures but also the efficiency of the design process.In this paper, a 86m-span double-layer spherical lattice shell and a 60m-span double-layer cylindrical lattice shell were taken as case studies. The behavior of the lattice shells under wind load and earthquake action was studied. The effect of wind load and earthquake action on the needed weight of the steel was analyzed. Following conclusions were obtained: 1. for the double-layer spherical lattice shell, wind load has little effect on the lattice shell. Though the earthquake action has obvious effect on the axial forces of the diagonal members, it has little effect on the design of the lattice shell because the sections of these members are controlled by their slenderness ratios; 2. for the cylindrical lattice shell, wind load is one of the control loads. The needed weight of the steel is proportional to the wind load. Earthquake action has little effect on the design of the lattice shell.Base on the analysis of special load effects, reasonable wind load and earthquake load were determined. Design standardization and economy comparison were completed for both lattice shell structure.Since the cement mill is often built in remote areas with bad geological condition, the effect of uneven foundation settlements on the behavior of the lattice shells was studied. It was shown that the uneven foundation settlements only increase the internal force of nearby members. The larger the settlements, the more members are affected. The internal forces caused by the uneven foundation settlements should be considered in the design of the lattice shells especially for bad geological condition.