Performance based assessment of rammed aggregate piers

2015-09-17
Within the confines of this paper, a normalized displacement-based capacity mobilization scheme is presented for rammed aggregate piers (RAP). For this purpose, field load tests, performed on 63 RAPs, in Turkey, were assessed. Site investigations at these sites revealed that generalized soil profiles are mostly composed of normally consolidated clay layers extending to a depth of 18 m. Below this depth, usually medium dense to dense sand / hard greywacke / very stiff to hard clay layers are present. A weighted mean SPT N6o assessment procedure was utilized to estimate representative soil strength and stiffness parameter in cohesive soils. The results of RAP load tests were summarized in the form of normalized mobilized capacity versus settlement curves as a function of representative SPT N60 values. The normalized field load test database revealed that: i) the shaft resistance is observed to be fully mobilized at normalized displacements of 40 % of RAP diameter for very soft clays and at 10 % of RAP diameter for firm clays, ii) up to normalized displacements of 2-5% of RAP diameter, 30-50% of the shaft resistance capacity is mobilized in a rather linear elastic manner, iii) normalized capacity mobilization response of RAPs is more flexible than the ones of bored concrete piles, iv) under compressive loads, RAPs exhibit a strain hardening response, as a result of which, the design-basis capacity is dominated by allowable settlement criterion. The proposed normalized capacity and displacement response curves, presented herein enable displacement (performance)-based assessment and design of RAPs.
16th European Conference on Soil Mechanics and Geotechnical Engineering, ECSMGE 2015

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Citation Formats
K. Ö. Çetin and Ö. Lale, “Performance based assessment of rammed aggregate piers,” Edinburgh, United Kingdom, 2015, p. 1059, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/87398.