STAGED CONSTRUCTION OF AN INTERSTATE I69 EMBANKMENT: COUPLED HYDROMECHANICAL NUMERICAL SIMULATION

摘要

New embankments were constructed mostly on soft clays as part of interstate I69 extension in southernrnIndiana. The embankments serve as bridge abutments and as part of the fill sections along the interstaternextension alignment. The height of the embankments range from 50-ft to 125-ft with a maximum foundationrnthickness of about 75-ft. The foundation soils comprise relatively high compressible fine grained soils. Arnfully coupled Hydro-Mechanical numerical simulations were conducted for optimizing the constructionrnstages of the embankments. The objective of the staged construction is to allow for sufficient effective stressrnand undrained shear strength gain to ensure foundation stability under the stage load. Wick drains werernutilized to shorten the drainage path and thus accelerate achieving the required undrained shear strength.rnThe extensive field investigation and laboratory testing programs provided a good understanding of thernsubsurface conditions and allowed the use of a relatively advanced soil constitutive model in the numericalrnsimulations of the staged construction. The effectively designed instrumentation program allowed forrnmonitoring the settlement and pore water dissipation during construction. The pore water pressure, andrnsurface and subsurface settlements from the numerical model predictions reasonably agreed with therninstrumentation data over the construction period.