Settlement of Buildings Constructed in Hackensack Meadows

Abstract

Observation of several one-story buildings in Hackensack Meadows constructed over lightly preconsolidated varved clay deposits reveal discrepancies between estimated and measured settlements. Case histories indicate underestimates of settlement for buildings where combined applied fill and building loads are about 1,500 psf, and apparent overestimates where applied loads are less than 900 psf. Structural distress was minor or nonexistent where deflections of 1:240 to 1:400 were measured, as a result of differential settlement. Changes in laboratory consolidation test techniques produced no improved method for estimating settlement. Field slope indicator readings indicated horizontal deformation to be minor. Field data has provided an empirical method for estimating settlement in vicinity when loading and subsoil conditions are similar. Further research and field data of a regional nature is needed to better understand and define the strain characteristics of varved clays of this area under relatively light loads.