Modified Analytical Solution to Radial Consolidation with Soil Characteristics in a Disturbed Zone

Abstract

An analytical solution modified from Hansbo's equation is suggested to evaluate the degree of radial consolidation, considering the consolidation characteristics of remolded clay and variation of soil properties within the disturbed zone. With increasing k(h)/k(s), the time factor T-h for a certain degree of radial consolidation continuously increases, while the time factor T-hs slightly decreases and finally converges to the almost identical <(U)over bar>(')(r)'-T-hs relation. Under the assumption that the settlement occurred between the prefabricated vertical drain (PVD) installation and the surcharge load application is resulted from the reduction of void ratio within the disturbed zone, the radius of the disturbed zone is estimated to be 2.675 r(m) for a disturbed zone of constant permeability or void ratio, while radii of the transition zone and fully disturbed zone are found to be 4.1 r(m) and 1.0 r(m), respectively, for a disturbed zone with linear variation in the void ratio. The settlement vs. time relation predicted by the suggested solution is in good agreement with the settlement measured at Busan Newport site when k(h)/k(f) values of 2.5 and 5.0 are used for clay layers located above and below EL - 30m, respectively, and linear variation of the void ratio within the disturbed zone is assumed.