A Case Study of Complex Site Characterization of the Honolulu Transit Corridor Project in Honolulu, Hawaii

This paper presents a site characterization case history for an 11.6-km (7.2-mile) fixed-guideway transit system in the corridor between East Kapolei and Pearl Highlands, on the Island of Oahu, Hawaii. The relatively young age of the volcanic island and the sea level fluctuations during the continental glaciation cycles produced complex subsurface material combinations, which is unique only to Hawaii. As a result, subsurface material distribution and their engineering properties could vary significantly within short distances and are hard to predict accurately. A carefully selected sampling/testing program was implemented to provide a conceptual vision into the subsurface profile and to estimate the subsurface material properties and their engineering performance. The subsurface exploration program included conventional approaches (i.e. soil borings, SCPTu, SSWV, and ReMi^TM) but with some variations to account for local conditions and practices. From the generalized subsurface profile along the project alignment, the profile indicated variable distribution and material properties in the subsurface typical of the highly variable ground conditions encountered in Hawaii.