Why Do Soil Tests Differ?
Soil is not a uniform material — its layers change with depth, and its characteristics vary from site to site and city to city. That is why each construction project requires specific tests based on soil type and structure.
Standard Penetration Test — SPT
What Is It?
The SPT is the most widely used field test in soil investigations. Performed during boring, it measures the number of blows required to drive a standard sampler 30 cm into the soil. The N-value gives a direct indicator of soil strength and classification.
When Do You Need It?
- ✔️ All soil reports for residential and commercial buildings
- ✔️ Determining the appropriate foundation type (footings / raft / piles)
- ✔️ Assessing liquefaction risk in sandy soils
- ✔️ Mandatory per SBC 303
California Bearing Ratio — CBR
What Is It?
CBR measures soil or pavement layer resistance to penetration, expressed as a percentage relative to a standard crushed stone. The higher the value, the better the soil performs as a road base.
When Do You Need It?
- ✔️ Road and street pavement layer design
- ✔️ Evaluating subbase and subgrade for paving
- ✔️ Airport and industrial complex projects
Plate Load Test
What Is It?
A steel plate is placed on the soil and incremental loads applied to measure actual bearing capacity and expected settlement. It is the most accurate field method for determining bearing capacity for large building foundations.
When Do You Need It?
- ✔️ Towers and high-rise buildings
- ✔️ When SPT results are inconclusive
- ✔️ Verifying bearing capacity before major foundation pours
Nuclear Density Test
What Is It?
Uses nuclear gauges to instantly measure soil or asphalt density and moisture content on-site without lab samples. Used to verify compaction percentages after backfilling.
When Do You Need It?
- ✔️ Accepting backfill layers in projects
- ✔️ Road layer compaction testing
- ✔️ Immediate on-site results
Asas Laboratory Company provides all of these tests in Makkah, Jeddah, Madinah, Riyadh, and Qassim with a certified field team and calibrated instruments.