The primary reason for geotechnical investigations is to find possible anomalous subsurface
conditions before beginning a project. The costs of not performing a geotechnical investigation
can be astronomical and in rare cases cause irrecoverable costs. AKMG provides geotechnical
investigation services and construction material monitoring services throughout all phases of
feasibility/planning, design development, construction, and post-construction.

Commonly reffered to as Soil Investigation or Ground investigation, is a techqniue in Geotechnical
Engineering employed to assess the surface and subsurface condition to determine engineering
properties of soil or rock core both in-situ and in Laboratory. This testing is carried out for soil or
rock formations by conducting on-site explorations, boring, sampling, logging and laboratory
testing. Geotechnical studies help getting detailed data on the geological conditions of the site
which gives a Geotechnical Engineer/Engineering Geologist, the sufficient data to recommend
foundation design or other related recommendations. The collected data is analyzed and
geotechnical criteria for foundations, retaining walls, site drainage, etc. are developed. In
geotechnical engineering the typical areas of recommendation include but are not limited to the
following:
• Foundation recommenadtions (deep and shallow)
• Piled foundations
• Slope stability
• Retaining walls
• Pavements
• Evaluation of exisiting foundations
• Ground improvement
The geotechnical or soil investigations are used in every civil engineering projects which are
related and not limited to the designing of shallow/deep foundations for buildings or other related
structures such as slope stability etc., for roads and bridges, dams, hydropower, wind, solar
power plants, transmission lines and grid stations, telecommunication towers, oil, and gas. It also
plays a vital part in establishing retaining structures, constructing underground structures such as
tunnels and quarries which are subjected to soil pressure from all sides, constructing earth dams
that require proper knowledge of engineering properties of soils and rocks. All in all, these
investigations play a crucial role in researching the impact of development on various construction
projects.

Geotechnical drilling is a method by which core samples of rocks and soil samples are recovered
and then tested both in-situ and ex-situ to determine engineering properties of these samples and
cores. This is a very integral part of soil investigation for any project as unstable and unsafe rocks
and soil could undermine the integrity of the site. Accurate drilling establishes a safe foundation
for whatever project the contractors are going to work on. Drilling in soil or rock formations is
performed in a wide range of ground conditions both in-shore and off-shore employing hand
auger drilling rigs, straight rotary rigs, reverse rotary rigs, light and heavy percussion rigs.
Different diameters of drilling can also be achieved by increasing the bit size.
Collection of disturbed and undisturbed samples (DS & UDS)
During drilling when we acquire the samples from the ground, we usually have two types of
samples; disturbed and undisturbed samples.
1. DISTURBED SAMPLES (DS)
When the structure, texture, density, natural water contents or the stress conditions of the
samples cannot be taken as in ”in-situ conditions”, we refer to it as disturbed samples.
However, these samples can be recovered.
2. UNDISTURBED SAMPLES (UDS)
Without disturbing the structure, texture, density, natural water contents or the stress
conditions of the sample is called an undisturbed sample. These are normally taken in
sample barrels such as Shelby, Denison and Pitcher samplers which retain the original in-situ
condition of soil samples when taken for tests in laboratory.

The Standard Penetration test (SPT) is common in situ testing method used to determine the blow
count commonly referred to as “N Values” of subsurface soils. The standard penetration tests are
carried out in borehole according to the ASTM standard (ASTM D1586).

Borehole logging is a time and money-saving approach to gaining detailed information which is
otherwise only obtainable from performing and analyzing numerous cores. Borehole logging data
is typically used to characterize geology, fracture patterns, fluid flow, and geologic structural
properties. Standard guide ASTM D5434 for field logging of sub-surface exploration of rock and
soil are followed.

Test pits are used for sampling and closely examining the engineering properties of soils. The plan
view of the pit is usually circular or rectangular. Test pits can be excavated through machinery or
hand tools. Test pits also give a close to in-situ condition of soil that can be tested in laboratory to
more accuracy to determine the engineering properties, this sampling technique is usually called
Block Samples that is carefully extracted from the pit, waxed and stored in a wooden box to
retain the original moisture

The Lugeon test, sometimes call also Packer test, is an in-situ testing method widely used to
estimate the average hydraulic conductivity of rock mass. It is indeed In situ test of formation
permeability performed by measuring the volume of water taken in a section of test hole when the
interval is pressurized at a given pressure (10 bars -150 psi). It is used primarily in variably
permeable formations under the evaluation of fracturating.
The test is named after Maurice Lugeon (1933), a Swiss geologist who first formulated the test.
Basically, the Lugeon test is a constant head permeability type test carried out in an isolated part
of a borehole. The results provide information about hydraulic conductivity of the rock mass
including the rock matrix and the discontinuities. The test is carried out as specified in ASTM
D6028 / D6028M – 20.

This test measures the seepage of water through the soil. There are several methods to perform
permeability tests such as falling head, constant head and laboratory methods that are carried out
in soils. The falling head method of determining permeability is used for soil with low discharge,
whereas the constant head permeability test is used for coarse-grained soils with a reasonable
discharge in a given time. For very fine-grained soil, the capillarity permeability test is
recommended. The knowledge of this property is much useful in solving problems involving yield
of water-bearing strata, seepage through earthen dams, the stability of earthen dams, and
embankments of canal bank affected by seepage, settlement, etc.

The field density test is conducted to find out if the specified compaction has been achieved in
the soil layers in the field. Sand replacement method or sand cone method is commonly used to
determing the field density. The procedure of the test is performed accurately as specified in
ASTM D446-82 standards.

Grout is a mixture of cement, sand and water which is used to fill the gaps in any structure such
as concrete, tiles, water proofing etc.

 

WHY US?

AKM Geotechnical provides a comprehensive range of geotechnical investigation services and
believes that an efficient and effective geotechnical study is an integral component of any
proposed civil engineering project. We ensure that the soil investigation and soil testing is
designed and implemented correctly to meet the project requirements. Where necessary, our
multi-disciplined teams are able to integrate the scope of work to cover both geotechnical and
environmental concerns in order to provide a technically robust and cost-effective site
investigation solution.

 

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