ABSTRACT:

Geotechnical boring data in the Mississippi River Delta from River reach km 0 (Head of Passes) to km 108 (Jesuit Bend). The data is recorded in the Unified Soil Classification System.

ABSTRACT:

Complex subsurface geology of coastal Louisiana, formed under fluvial, deltaic, and sea level influences, increases the uncertainty in design and construction of hard and natural infrastructure. In this study, twenty-four (24) collocated soil borings and CPTs at the Inner Harbor Navigation Canal (IHNC) in New Orleans, Louisiana were used to construct multiple three-dimensional soil stratigraphy models by ordinary kriging. To explore the spatial distribution of soils at the site, four soil stratigraphy models were established, including the unified soil classification system (USCS) from borings and three constructed using soil behavior type (SBT) correlations.

ABSTRACT:

Wetlands in the Mississippi River Delta Plain (MRDP) have been suffering from a high rate of land loss. Sediment cores have been drilled into the wetlands to understand their growth and degradation, and to provide subsurface information for the coastal protection and restoration projects. However, few three-dimensional (3-D) stratigraphy models have been developed for the wetlands on a regional scale, due to difficulties in correlating large amount of spatial scattered subsurface data and integrated visualization of stratigraphic features and topobathymetric features. In this study, a 3-D model was constructed in the Lower Barataria Bay (LBB) and the Lower Breton Sound (LBS), covering an area of 190 km2 and extending from 0.5 m to -4 m in elevation. Sediment composition (sand%, silt% and clay%) was spatially interpolated, using a compositional kriging method, extended from ordinary kriging by a log-ratio transformation. Instead of visualizing three composition components independently, sediment composition was translated into sediment texture to be visualized as sediment types. Modeling results intuitively show spatial distribution of stratigraphic features and their spatial relationships with topobathymetric features such as marsh surface, river channel and dredging channels. Results show a silty depositional package, which consists of crevasse splays and periodic overbank flooding deposits, made up the largest portion of the wetlands. A clayey blanket is observed to cover most part of the LBB and landward side of the LBS. A large area of clayey blanket in the seaward part of the LBS has apparently been eroded away, which is likely caused by coastal reworking processes.