9412906 Pincheira Precast construction using double-Tee members is common in parking garages, commercial and industrial buildings across the United States and has had wide success because of its proven efficiency an economy. the double-Tee's are used as walls and diaphragms. Unfortunately the systems were developed primarily for vertical load resistance. New areas of the country have recently been designated as seismically active and building codes have tightened their seismic design requirements. These changes have cast doubt on the use and capacity of precast structural systems, and lack of thorough evidence to the contrary will likely result in more conservative design required by future codes. The goal of this project to establish a proven physical basis for connection capacities between thin concrete flange sections such as joint between double-Tee's used as wall or diaphragm panels to improve design methods for seismic resistance. To achieve the objective extensive cyclic connection testing will be carried out. The connection test results will be used to develop nonlinear analysis methods and to suggest code changes such as: rational methods of selecting flange or diaphragm thickness and topping thickness if needed, means of estimating appropriate load reduction factors for precast double-Tee shear walls, steps in designing ductile flange connections between members, and examples showing non linear design procedures for jointed precast prestressed diaphragms and walls. This is a PRESSS project. ***
