【Daily Discussion】Public Utilities – Water Resources and Hydropower – 20210214

This post was last edited by Zhongyuanren on 2021-2-14 at 13:14. A load combination refers to several loads that may occur simultaneously on a structure during design, taking into account factors such as the building’s characteristics, usage requirements, natural conditions in its location, the nature of the loads, and the probability of their occurrence. There are six types of design load combinations: one or more of the basic variable loads combined with one or more of the permanent loads; one or more of the basic variable loads combined with one or more of the permanent loads and one or more of the other variable loads; combinations based on possible construction loads for checks during the construction phase; and one or more of the structural weight, prestress, soil weight, and earth lateral pressure combined with seismic forces. Due to the different nature of loads, the probabilities of various load combinations also vary. Therefore, for different load combinations, structures should have different safety margins, meaning that the safety factors should differ as well.

In design based on limit states, it is a combination of the design values of various load effects occurring simultaneously, established to ensure the reliability of the structure. The so-called load effect refers to the internal forces or displacements of a structure under the action of a certain load. Combining various load effects in a certain pattern according to probability statistics and reliability theory is known as load effect combination. The loads acting on the gravity dam body include the following, and load combinations need to be considered: 1. The loads acting on a gravity dam comprise the weight of the dam body itself, water pressure on the upstream and downstream dam surfaces, uplift force, wave pressure or ice pressure, sediment pressure, as well as seismic loads. 2. A gravity dam is a large-scale water-retaining structure built from concrete or stone masonry; its basic cross-section is that of a right triangle, and it consists of several dam sections as a whole. Under the action of water pressure and other loads, gravity dams rely primarily on the frictional force generated by their own weight to meet stability requirements; at the same time, they depend on the pressure exerted by their own weight to counteract the tensile stresses caused by water pressure, thereby satisfying strength requirements. A dam that relies primarily on its own weight to remain stable under water pressure and other external loads. The cross-section of a gravity dam is generally triangular, and the materials used for constructing it are concrete or rubble masonry.

A load combination refers to several loads that may occur simultaneously on a structure during design, based on factors such as the building’s characteristics, usage requirements, natural conditions in its location, the nature of the loads, and the probability of their occurrence. There are six types of design load combinations: one or more of the basic variable loads combined with one or more of the permanent loads; one or more of the basic variable loads combined with one or more of the permanent loads and one or more of the other variable loads; combinations based on possible construction loads for checks during the construction phase; and one or more of the structural weight, prestress, soil weight, and earth lateral pressure combined with seismic forces. Due to the different nature of loads, the probabilities of various load combinations also vary. Therefore, for different load combinations, structures should have different safety margins, meaning that the safety factors should differ as well.

A load combination refers to several loads that may occur simultaneously on a structure during design, based on factors such as the building’s characteristics, usage requirements, natural conditions in its location, the nature of the loads, and the probability of their occurrence. There are six types of design load combinations: one or more of the basic variable loads combined with one or more of the permanent loads; one or more of the basic variable loads combined with one or more of the permanent loads and one or more of the other variable loads; combinations based on possible construction loads for checks during the construction phase; and one or more of the structural weight, prestress, soil weight, and earth lateral pressure combined with seismic forces. Due to the different nature of loads, the probabilities of various load combinations also vary. Therefore, for different load combinations, structures should have different safety margins, meaning that the safety factors should differ as well.

A load combination refers to several loads that may occur simultaneously on a structure during design, based on factors such as the building’s characteristics, usage requirements, natural conditions in its location, the nature of the loads, and the probability of their occurrence. There are six types of design load combinations: one or more of the basic variable loads combined with one or more of the permanent loads; one or more of the basic variable loads combined with one or more of the permanent loads and one or more of the other variable loads; combinations based on possible construction loads for checks during the construction phase; and one or more of the structural weight, prestress, soil weight, and earth lateral pressure combined with seismic forces. Due to the different nature of loads, the probabilities of various load combinations also vary. Therefore, for different load combinations, structures should have different safety margins, meaning that the safety factors should differ as well.