Design Reliability for Estimating Cost of Pile Foundations.

摘要

As the design process is now developing within the Army Corps of Engineer's, it is becoming necessary to estimate costs with high levels of accuracy at the time of the feasibility report. Experience has shown that the accuracy requirements may not be met by current estimating practices. Discussions with designers reveal that the primary cause of poor cost estimates is not a failure to correctly assess unit construction costs but rather a poor judgement of the structure itself. For example, if the foundation type is incorrectly anticipated a large change in cost occurs. In this Phase I report a conceptual model dor design reliability was developed. A regression analysis method was used to develop a linear cost function using statistical data. Fuzzy set theory was then used to get both the design fuzzy probability and the design membership function. Sensitivity analysis was also used to identify the critical variables of the problem. A computer program was developed. The program listing and the user manual are given in the appendices. The proposed conceptual model for design reliability will be used to estimate the cost of pile foundations. A particular project will be selected and design uncertainties will be assesses by the researchers working in cooperation with engineers from the New Orleans District who will provide the required data. The membership design function data must be assembled.