Research The Roofing Photovoltaic Design Value Of Load

In the field of structure engineering, the probabilistic limit state design method based on the probabilistic theory is currently accepted worldwide, which is mostly used in international standard and European codes. China is one of the countries where limit state design method was adopted in the early times of the 19th. This paper is available in design theory to research the problem about the photovoltaic load design value, finally to be sure that if we design photovoltaic building according to the exiting design specifications can meet the requirement of reliability.As one of the most important emerging industry in 21 century, BIPV has caused various countries to take it seriously. With the increasingly use of photovoltaic PV installation and often for large-area laying, photovoltaic load on the influence of the building structure cannot be ignored. But on the current load code without considering the photovoltaic load and loading effects on structures. The paper is to solve such a problem, determine standard photovoltaic load and establish the general design expression which applied to photovoltaic building.Photovoltaic always installs on roof, balcony, patio, metope, corridor tend and so on, and the most common carrier is the roof. This paper discusses photovoltaic on flat roof, slope roof all kinds of installation plan corresponding load value. Roof photovoltaic load divided into persistent live load and temporary live loads two parts. Then calculate the local load value according to different installation process corresponding. Finally According to the building structure load code, the load code will be transformed into uniformly distributed load. The standard value of the design load depends on the application of the mathematical statistical analysis method. According to the principle of the probability limit state calculation, we calculate the optimal load coefficient when separately consider the case that combine constant load and live load of roof photovoltaic and when considering four kinds of load effect combination. Finally, On this two cases to determine the subentry coefficient and compare with the subentry coefficient of load specification,determine the universal design expression.