*** 9760627 Samman This Small Business Innovation Research Phase I project will conduct research on a novel laser-based device that will accurately measure surface roughness of drilled shaft boreholes. Drilled shafts are foundation elements whose capacity is derived predominantly from the shear resistance developed at the rough interface between the shaft and the surrounding geomaterial. Current design methods ignore roughness and instead are generally based on past experience and rules of thumb. This ultimately leads to shaft designs that are perhaps overly conservative and expensive. Over the last ten years, theoretical models have been developed to include roughness in all stages of the design process. However, until shaft roughness can be measured accurately in situ, it is unlikely that these models will reach their potential, nor will the potential cost savings to society be realized. In Phase I, the feasibility of the proposed device will be established by: (1) measuring the accuracy and establishing the limitations of laser range sensors, and (2) assessing the cost and challenges associated with developing a prototype device that ensures satisfactory field performance. The annual US market for drilled shafts is estimated at $1 billion per year. This research will ultimately lead to shaft designs that are conservative yet economical. A moderate 20% reduction in shaft lengths would translate to a saving of some $150 million annually in the US alone. Because of its strong potential, the Federal Highway Administration has expressed interest in providing supplementary funding and the International Association of Foundation Drilling has also indicated a willingness to support the research project. ***
