Читать книгу Earthquake Engineering for Concrete Dams - Anil K. Chopra - Страница 20

Traditional design procedures greatly underestimate seismic demands imposed on both arch and gravity dams, as well as the capacity of these structures to resist these demands. The seismic forces associated with the mass of the dam and the hydrodynamic pressures are underestimated, as mentioned earlier. The tensile strength of concrete, which is not insignificant, is essentially ignored in the no‐tension requirement in the design criteria for gravity dams and by the small value allowed for arch dams. A progressive, systematic approach to computation of seismic demands and evaluation of structural capacity is presented in Chapter 12.

Methods for designing dams must be improved in at least two major ways: (i) the tensile strength of concrete should be determined by testing cylindrical cores that are large enough – diameter equal to three or four times the size of the coarse aggregate; and (ii) seismic demands should be computed by dynamic response analysis of the dam–water–foundation system. Development of such analysis procedures is one of the main thrusts of this book.