For the effective stress analysis, ชชช c′and f′could be obtained from consolidated undrained triaxial compression test movement s with pore pressure measurements (e.g., see test data in Sec. 3.5.2). If the groundwater table is shallow, its effect may need to be included in the analysis (i.e., use buoyant unit weight). Ignoring the effective cohesion of the soil, Eq. 6.27 could be used to determine the passive resistance of the pile or pier. Depending on the amount of allowable lateral movement, usually only the upper few feet of soil will be subjected to passive pressure. For soft cohesive soil that is highly plastic and creeps around the pile such as shown in Fig. 6.17, there could be additional lateral deflection of the pile head.