where qc=measured cone resistance,

where qc=measured cone resistance, and other parameters aredefined above.Lunne et al. (1985) found that NΔu correlated well with Bq and therelationship varied between 4 and 10. However, Karlsrud et al. (1996)indicated that there was no clear dependency of NΔu on Bq. It isFig. 1. Distribution of Lianyungang marine clay sediment.S.Y. Liu et al. / Engineering Geology 121 (2011) 66–74 67difficult to correlate NΔu and Bq by a simple empirical equation. In thisstudy, the relationship between NΔu and Bq was approximately takenas the average one of the upper and lower range outlined by Lunne etal. (1985). At a specific depth, with the Bq value calculated by Eq. (4),the corresponding NΔu value was then determined.In Eq. (2), M value was derived as 0.92 from the confinedundrained triaxial shear tests of the soils sampled from borehole BH-2. Terzaghi et al. (1996) indicated that effective friction angle φ′ had agood relationship with plasticity index Ip for various clays. For thesamples presented in this study, Ip values are close to each other atdifferent depth (see Fig. 10), indicating that φ′ values would be closeto each other. As a result, M values would be close to each other atdifferent depth based on Eq. (6). Therefore, the CU tests wereconducted only on soils sampled at 6 m depth, and M value of 0.92was used to calculate OCR using Eq. (2) for soils at other depths.