strain modeling. Deflection was measured at the top of the column and load at depth was analyzed using strategically placed strain gauges at various depths along the length of the column. Each of the four rigid inclusion compression tests performed well at the 57 kip (254 kN) design load, the 86 kip (383 kN) test load and beyond. The observed maximum deflection at the design and test loads was between 0.2-0.4 in (5-10 mm) for each test indicating ideal end bearing conditions for the elements. Full-Scale Load Tests In addition to the single-element static load tests, a fully instrumented area load test covering 43 rigid inclusions was also performed. The purpose of the area load test was to verify performance of the entire ground improvement system including the efficiency of load transfer through the interaction of the LTP with the rigid inclusion. Fill above the rigid inclusions was built up incrementally to a maximum height of twice the final fill height with hold periods at various levels to match the anticipated construction sequence across the rest of the roadway. Additional fill and settlement plate readings after planned finished grade achieved Deflection during the area load test was measured with eight settlement plates placed both between and directly above the rigid inclusions to observe differential settlement across the spacing. Four controlled modulus columns were instrumented with strain gauges, similar to the single-element tests, to measure load along the length of the rigid inclusions. Three vertical inclinometers were installed to measure lateral deflections across the width and along the length of the roadway for comparison with movements expected from the design. Two vibrating wire piezometers were placed to measure increases in pore water pressure; excessive buildup of pore water pressure would indicate the added stress from the placed fill reaches the soil beneath the LTP instead of being transferred into the rigid inclusions. Excessive buildup of pore water pressure would indicate the added stress from the placed fill reaches the soil beneath the LTP instead of being transferred into the rigid inclusions. Area load test layout plan DEEP FOUNDATIONS * JAN/FEB 2024 * 75