A rational method of optimum design of disaster resistant structures should have following characteristics: multi - stage optimization, consideration of both the cost and the loss expectation of the structure in the objective function, multi - failure criteria for the structure, practical to use and consistent with the National Design Codes.

The earthquake-resistant design of jacket platform based on optimal fortification intensity is dis- cussed with Platform BZ28-1 of Bohai Oil Field in China taken as an example,following the principle of three-level fortification and two-stage aseismic design of buildings and both cost and loss expectations taken in- to consideration.

In consideration of cost and whole life loss expectation of product, the whole life optimization design model with control parameter of dynamic reliability is proposed.

Through studying on the factors that influence parking capacity,the paper puts forward the model of parking capacity based on minimal expected loss and the method of solving the model in the center business district from the asp.

the optimum value of α-level was obtainedunder the goal of the expected loss for each test.

Employing the concept of expected loss of risk and the loss function in the case study, conomic benefits of flood control, hydrological network as well as flood forecast are computed respectively.

Coupling analysis of long-term prestress loss and slope creep;