Louisiana experiences some of the highest subsidence rates in North America. Coastal parishes are subsiding at rates of 0.5–1.5 inches per year as compressible deltaic sediments consolidate, organic soils oxidize, and deep geological faults continue their downward displacement. This relentless ground loss damages highways, rail lines, pipeline supports, and building foundations across the coastal plain and delta region.
The Mississippi River delta, Atchafalaya Basin, and Lake Pontchartrain margins are particularly affected. Highways built on deltaic soils settle unevenly, creating ride-quality failures and structural distress at bridge approaches. Pipeline supports lose bearing capacity as the ground beneath them compresses. Levee systems lose freeboard as the ground they sit on subsides below design elevations.
Compaction grouting densifies the compressible soil layers driving subsidence—arresting ongoing settlement and restoring infrastructure to design grade. GSI's engineers design injection programs targeting the specific stratigraphic layers responsible for consolidation, using borings and CPT data to identify treatment zones precisely.
When structures have already settled beyond acceptable tolerances, underpinning transfers foundation loads to competent strata below the compressible zone. GSI installs micropiles or helical piers through Louisiana's soft deltaic soils to bearing layers at depth—then hydraulically relevels the structure to design grade.
Where subsidence is driven by loose, permeable sand layers consolidating under load, permeation grouting fills pore space and cements soil grains in place—increasing bearing capacity and reducing future compressibility. This approach treats the soil mass rather than bypassing it with structural elements.
Subsidence repair techniques that work in sandy coastal plains or limestone terrain fail in Louisiana's organic-rich deltaic environment. GSI engineers for the ground Louisiana actually presents:
Every month of continued settlement increases structural stress and repair cost. GSI's deltaic soil specialists design treatment that targets the layers driving your Louisiana subsidence.
