Geotechnical Engineering Abbreviations
Geotechnical engineers talk amongst themselves using abbreviations that project stakeholders and even engineers from other trades struggle to decipher. In this compilation, we present the tip of the iceberg. Readers who are not familiar with the abbreviations are invited to search online for more detailed information on what they mean.
100 Abbreviations Geotechnical Engineers Use
ACIP - Auger Cast-in-Place Pile
ACDP - Auger-Cast Displacement Pile
APGD - Auger-Pressure-Grouted Displacement (pile)
ASD - Allowable Stress Design
BMPs - Best Management Practices
BOF - Bottom of Foundation
CBR - California Bearing Ratio
CFA - Continuous Flight Auger (Pile): The same as an Auger Cast-in-Place Pile (ACIP).
CPT - Cone Penetration Test
CD - Consolidated Drained (triaxial test)
CMT - Construction Material Testing
COV - Coefficient of Variation
CU - Consolidated Undrained (triaxial test)
DEM - Discrete Element Method
DFI - Deep Foundations Institute (https://dfi.org/)
DGWD - Design Groundwater Depth
DIGGS - Data Interchange for Geotechnical and Geoenvironmental Specialists (https://www.geoinstitute.org/special-projects/diggs)
DST - Direct Shear Test
EGS - Existing Grade Surface
FDP - Full-Displacement Pile
FEM - Finite Element Method
FOS - Factor of Safety
GEOR - Geotechnical Engineer of Record
G-I - Geo-Institute (of ASCE) - https://www.geoinstitute.org/
GI - Ground Improvement
GM - Ground Modification
GWT - Groundwater Table: Typically, refers to the depth of the groundwater at a site.
IGM - Intermediate Geomaterials: Transition materials between soils and rocks.
ISSMGE - International Society for Soil Mechanics and Geotechnical Engineering (https://issmge.org/)
LEM - Limit Equilibrium Method
LL - Liquid Limit
LRFD - Load and Resistance Factor Design
LSD - Limit State Design
MASW - Multi-Channel Analysis of Surface Waves
MPC - Modified Proctor Compaction
MSE - Mechanically Stabilized Earth
MDD: Maximum Dry Density
MSL - Mean Sea Level
MWD - Monitor (or Measure) While Drilling
NC - Normally Consolidated (clay)
OC - Over-consolidated (clay)
OCR - Over-consolidation Ratio
OMC - Optimum Moisture Content
PBD - Performance Based Design
PDA - Pile Driving Analyzer
PI - Plasticity Index
PL - Plastic Limit
PLT - Pile Load Test
PLT - Point Load Test
PPT - Pocket Penetrometer Test
RAP - Rammed Aggregate Pier
RBD - Reliability (or Risk) Based Design. We prefer reliability 👍.
RC - Relative Compaction (=field dry density divided by maximum dry density, expressed as a percentage)
RCT - Resonant Column Test
RI - Rigid Inclusion
RQD - Rock Quality Designation
SCPT: Seismic Cone Penetration Test
Sl - Shrinkage Limit
SOE - Support of Excavation (system)
SOG - Slab on Grade
SPC - Standard Proctor Compaction
SPT - Standard Penetration Test
SRF - Stress Reduction Factor
SSA - Slope Stability Analysis
SSD - Saturated Surface Dry (of an aggregate)
SSI - Soil-Structure Interaction
SWPPP - Storm Water Pollution Prevention Plan
TBM - Tunnel Boring Machine
TOC - Top of Concrete (elevation)
UC - Unconfined Compression (test)
USCS - Universal Soil Classification System: a system to classify soils into:
CH: Fat Clay
CL: Lean Clay
CL-ML: Silty Clay
GC: Clayey Gravel
GC-GM: Silty, Clayey Gravel
GM: Silty Gravel
GP: Poorly-graded Gravel
GP-GC: Poorly-graded Gravel with Clay
GP-GM: Poorly-graded Gravel with Silt
GW: Well-graded Gravel
GW-GC: Well-graded Gravel with Clay
GW-GM: Well-graded Gravel with Silt
MH: Elastic Silt
ML: Inorganic Silt
OL: Low-plasticity Organic Silt or Clay
OH: High-plasticity Organic Silt or Clay
SC: Clayey Sand
SC-SM: Silty, Clayey Sand
SM: Silty Sand
SP: Poorly-graded Sand
SP-SC: Poorly-graded Sand with Clay
SP-SM: Poorly-graded Sand with Silt
SW: Well-graded Sand
SW-SC: Well-graded Sand with Clay
SW-SM: Well-graded Sand with Silt
USM - Unsaturated Soil Mechanics
UU - Unconsolidated Undrained (triaxial test)
VST - Vane Shear Test
ZAV - Zero Air Voids (curve, in compaction testing)