SBIR-STTR Award

The objective of the proposed project is the conceptual development, design and fabrication of a large-scale stress cell system for laboratory simulation of in situ soil stress conditions. The purpose of the stress cell is to provide a cost-effective means to developing interpretative guidelines for and validating in situ devices and studying in situ testing and sampling techniques. The phase i proposal presents a technical approach to evaluating the overall feasibility of the proposed system. Consideration is given to evaluation of a cubical cell utilizing a modular design concept. Capabilities will include application of three principal stresses, control of saturation and pore water pressure and variation of lateral stress with depth or at specific locations to simulate different k(o) conditions. Instrumentation and data acquisition concepts will be addressed with respect to monitoring of soil response and control/ verification of soil conditions before, during and after testing. The proposed phase i effort will include a literature search and review, an evaluation of preliminary design criteria and instrumentation requirements, and assessment of available technology, preparation of conceptual design alternatives, development of an analytical model to assess design alternatives, and a summary evaluation of the overall feasibility of the proposed projects.

The objective of the proposed project is the design, fabrication and checkout of a large-scale stress chamber system for laboratory simulation of in situ soil stress condition. A primary purpose of the stress chamber system is to provide a cost-effective means of addressing comparing, and developing interpretative guidelines for and validating in situ devices and studying in situ testing and sampling techniques. Some other potential applications include l-g model tests, model plume tracking studies, study of cementing and aging effects on soils, study of the behavior of earth-rock mixtures, and study of thermal behavior of soils. The phase ii proposal effect will include the design of various components of the stress chamber system, preparation of design drawings, purchase of instruments/equipment, fabrication of the stress chamber system, transportation of the system of wes, assembly of the system at wes, and checkout of the system including a trial run with one soil type.