Overview
Foundation problems are the hardest and most expensive to fix after construction. A properly planned soil investigation, with enough boreholes, taken deep enough, and tested in a laboratory, is a small cost against the value of the building it protects.
The soil under a building decides what kind of foundation it needs. Across Bangladesh, ground conditions change sharply over short distances: filled land, soft clays, loose silty sands, and high groundwater are all common. A foundation designed without site data is a guess. Soil investigation measures the ground, and foundation analysis turns those measurements into a foundation type, depth, and capacity that the structural design can rely on.
When you need it
- Before the structural design of any multi-storey building.
- The plot is filled land, low-lying, or close to a pond, river, or wetland.
- You plan to add floors to an existing building.
- Cracks or uneven settlement suggest a foundation problem.
- The approving authority asks for a soil report with the application.
What's included
- 01
Boreholes and SPT
Boreholes drilled to the required depth, with standard penetration tests (SPT) at regular intervals.
- 02
Soil sampling
Disturbed and undisturbed samples collected and logged for laboratory testing.
- 03
Laboratory testing
Grain size, Atterberg limits, moisture content, unit weight, unconfined compression, and consolidation where needed.
- 04
Groundwater observation
Groundwater levels recorded, because they affect bearing capacity, excavation, and basement design.
- 05
Bearing capacity and settlement
Allowable bearing pressure and expected settlement calculated for the proposed building.
- 06
Foundation recommendation
Shallow, mat, or pile foundation, with the recommended depth, capacity, and construction notes.
How it works
- 01
Plan the investigation
The number and depth of boreholes are set from the building's size, loads, and footprint.
- 02
Field work
Boreholes are drilled, SPTs are recorded, samples are collected, and groundwater is observed.
- 03
Laboratory testing
The samples are tested to classify the soil and measure its strength and compressibility.
- 04
Analysis and report
Results are analysed and the foundation recommendations are issued with the report.
What you receive
- Soil investigation report
- Borehole logs, SPT N-values, laboratory results, and the soil profile across the site.
- Borehole location plan
- Where each borehole was drilled in relation to the proposed building.
- Foundation recommendations
- Foundation type, depth, and allowable capacity, with pile capacities where piles are needed.
- Engineer's interpretation
- A plain-language summary of what the results mean for the design and the construction.
Codes & inputs
- ASTM D1586Standard test method for the standard penetration test (SPT) and split-barrel sampling of soils.
- BNBC 2020Requirements for site investigation and foundation design in Bangladesh.
Questions about soil & foundation
How many boreholes does my plot need?
It depends on the size of the building footprint, the number of floors, and how variable the ground is. Small residential plots typically need a few boreholes, while larger or taller buildings need more and deeper ones. We set the number and depth so that the whole footprint, and the depth that the foundation stresses reach, are properly represented.
Do I need a soil test before structural design?
For any multi-storey building, yes. The foundation type, depth, and size depend on the strength of the soil and the groundwater level, and these vary greatly from plot to plot in Bangladesh. Designing without soil data means either guessing, which is risky, or over-designing to be safe, which is expensive.
What is an SPT N-value?
The standard penetration test (SPT) counts how many blows of a standard hammer are needed to drive a sampler 300 mm into the soil at the bottom of a borehole. That count is the N-value. Higher values mean denser or stiffer soil. N-values at each depth, together with laboratory results, are used to estimate bearing capacity and pile capacity.
