25/01/2026
π¦ WHAT IS GEOTECHNICAL INVESTIGATION WORKS?
Geotechnical Investigation =
π Studying the soil and ground conditions before construction
π To know how strong the soil is and what type of foundation is needed
In simple words:
β‘οΈ It tells engineers what is under the ground.
β‘οΈ It checks if the soil can carry the weight of the building, tank, pipeline, or structure.
β‘οΈ It prevents future problems like settlement, cracks, sliding, or collapse.
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π© WHY IS GEOTECHNICAL INVESTIGATION IMPORTANT?
Because different soils behave differently:
β’ Some are strong
β’ Some are weak
β’ Some expand with water
β’ Some can cause sinking
Geotechnical investigation helps engineers design the safe foundation.
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π« WHAT ARE THE MAIN ACTIVITIES?
1οΈβ£ Soil Boreholes (Drilling)
Machines drill holes into the ground (5m β 40m deep).
Soil samples are taken at different depths.
Meaning:
π To know what type of soil exists below the surface.
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2οΈβ£ Soil Sampling
Two types:
β’ Disturbed sample (loose soil)
β’ Undisturbed sample (intact soil)
Meaning:
π Samples are sent to the lab for testing.
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3οΈβ£ Laboratory Testing
Tests include:
β’ Moisture content
β’ Grain size analysis
β’ Atterberg limits
β’ Density
β’ Shear strength
β’ Compaction
β’ Bearing capacity
Meaning:
π To measure how the soil behaves under load.
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4οΈβ£ Field Tests
β’ SPT (Standard Pe*******on Test)
β’ Plate load test
β’ Cone pe*******on test (CPT)
β’ Permeability test
Meaning:
π To check the strength of the soil directly on site.
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5οΈβ£ Groundwater Level Check
They measure how deep the water table is.
Meaning:
π This affects foundation design, dewatering, and basement works.
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6οΈβ£ Geotechnical Report
A final report that includes:
β’ Soil layers
β’ Lab + field test results
β’ Bearing capacity
β’ Allowable foundation loads
β’ Recommended foundation type (raft, piles, strip)
β’ Groundwater level
β’ Excavation recommendations
Meaning:
π This report tells engineers how to design the foundation safely.
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π§ SUMMARY IN ONE LINE
Geotechnical Investigation = Testing the soil to know if it can support the structure and what foundation is required.