Geotechnical Investigation
These services require specialists in geotechnical investigation and special equipment to conduct site and lab testing.
Our center owns three different types of rigs which could be utilized to perform testing in different conditions such as in open area like fields, roads and construction plots, and in narrow areas as in old cities and historic sites.
Our experience reached a comparatively high level of investigations for cement industry potential, quarry reserves for stone crushing to produce aggregates and so on.
Our routine business where boring and sampling is a common task to investigate soil bearing capacity, slope stability studies, design of retaining walls.
- Field Tests
- Lab Tests
- Geophysical survey
- Pile Integrity Test
- Static Plate Bearing Test
- Static Pile Load Test
Special field tests like Standard Penetration test (SPT), Cone Penetration Test (CPT), Shelby Sample, Vane Shear Test, Continuous Coring (Wireline Method), Permeability Test, Plate Bearing Test, Pile Integrity Test and Static Pile Load Test are also common in our performance.
Standards Penetration Test (SPT): –
The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil he main purpose of the test is to provide an indication of the relative density of granular deposits, such as sands and gravels from which it is virtually impossible to obtain undisturbed samples. The great merit of the test, and the main reason for its widespread use is that it is simple and inexpensive. The soil strength parameters which can be inferred are approximate, but may give a useful guide in ground conditions where it may not be possible to obtain borehole samples of adequate quality like gravels, sands, silts, clay containing sand or gravel and weak rock. In conditions where the quality of the undisturbed sample is suspect, e.g., very silty or very sandy clays, or hard clays, it is often advantageous to alternate the sampling with standard penetration tests to check the strength.
Rock Coring
It may be necessary to core rock if bedrock is encountered at a certain depth during drilling. It is always desirable that coring be done for at least 3.0 m. if the bed rock is weathered or irregular, the coring may need to be extended to a greater depth. a rock core samples are obtained by double – tube core barrels. On the basis of the length of the rock core obtained from each run (usually 1.5 m or 3.0 m) the rock designation ratio RQD can be obtained.
Corrosivity Test for Buried Pipeline and Other Test.
Special lab tests on soil samples are also part of our services such as:
• Triaxial Test
• Consolidation Test,
• Direct Shear Test,
• Permeability,
• Unconfined Compressive Strength,
• Point Load Test,
• Chemical Analysis, sulfate, chloride and pH value.
• Conductivity test.
Uniaxial compressive strength: –
The unconfined compression test is by far the most popular method of soil shear testing because it is one of the fastest and cheapest methods of measuring shear strength. The method is used primarily for saturated, cohesive soils recovered from thin-walled sampling tubes. The unconfined compression test is inappropriate for dry sands or crumbly clays because the materials would fall apart without some land of lateral confinement.
Properties of rocks are mainly used for the design of structures and characterization of intact rock materials. In rock engineering, the uniaxial compressive strength of rocks is generally defined as the failure strength of an intact rock specimen.
Triaxial Test: –
The Triaxial test is one of the most versatile and widely performed geotechnical laboratory tests, allowing the shear strength and stiffness of soil and rock to be determined for use in geotechnical design. Advantages over simpler procedures, such as the direct shear test, include the ability to control specimen drainage and take measurements of pore water pressures. Primary parameters obtained from the test may include the angle of shearing resistance ϕ΄, cohesion c΄, and undrained shear strength cu.
Geophysical survey such as: Vertical Electrical Sounding, Site seismic Survey, Electromagnetic survey.
Seismic Survey (MASW Method): –
The multichannel analysis of surface waves (MASW) method is one of the seismic survey methods evaluating the elastic condition (stiffness) of the ground for geotechnical engineering purposes. MASW first measures
seismic surface waves generated from various types of seismic sources—such as sledge hammer—analyzes the propagation velocities of those surface waves, and then finally deduces shear-wave velocity (Vs) variations below the
Surveyed area that is most responsible for the analyzed propagation velocity pattern of surface waves. Shear-wave velocity (Vs) is one of the elastic constants and closely related to Young’s modulus. Under most circumstances, Vs is a direct indicator of the ground strength (stiffness) and
therefore commonly used to derive load-bearing capacity.
Electrical Resistivity Survey: –
Electrical resistivity of the soil can be considered as a proxy for the spatial and temporal variability of many other soil physical properties (i.e. structure, water content, or fluid composition). Because the method is non-destructive and very sensitive, it offers a very attractive tool for describing the subsurface properties without digging. It has been already applied in various contexts like: groundwater exploration, landfill and solute transfer delineation, agronomical management by identifying areas of excessive compaction or soil horizon thickness and bedrock depth, and at least assessing the soil hydrological properties. The surveys, depending on the areas heterogeneities can be performed in one, two, or three-dimensions and also at different scales resolution from the cent metric scale to the regional scale
The Pile Integrity Tester performs Low Strain Impact Integrity Testing by the Pulse (or Sonic) Echo or Transient Response Methods. These methods are also collectively known as Pile Integrity Testing or Low Strain Dynamic Testing. The interpretation of PIT data may reveal potentially dangerous defects such as major cracks, necking, soil inclusions or voids and, in some situations, may determine unknown lengths of piles that support existing structures such as bridges or towers.
Bearing plate is used to in situ soil testing. The measurement is carried out under static load which allows us to specify geotechnical parameters of the subsoil. The entire analysis allows establishing density of the backfill layers and capacity when determining initial modulus, elastic modulus and subgrade reaction modulus. Survey is conducted under the influence of the static pressure exerted by a circular steel plate. The test characterizes zone to a depth of 30-50 centimeters below the plate. Assessment of compaction of the embankments/backfills is the basic test during the implementation of road investments.
The static pile load test gives the most accurate indication of the capacity of the in-place pile. It is performed using a reaction method. The test procedure involves applying an axial load to the top of the test pile with one or more hydraulic jacks. The reaction force is transferred to the anchor piles that go into tension in the case of a static load test in compression; or into compression in the case of a static load test in tension. Various forms of instrumentation are installed onto the test and anchor piles so that an accurate measurement of the test pile displacement can be obtained. Redundant systems are used to ensure accuracy of the various measurements.
