From geotechnical evaluation reports to foundation design, we can provide all the services you'll ever need to build build build!
Test Pits and Bulk Sampling
Teragrail GG offers manual test pit excavations in order to sample and study the composition and structure of the subsurface material. This is usually done simultaneously with site investigation and during pre-feasibility studies. Depending on the soil, test pits can be dug up to 10.0-m (with benching/shoring). Test pit excavations provide vital information on the material contacts, particle sizes and classification, extend of buried debris and other environmental factors that can affect the project site.
A borehole is a narrow vertical shaft bored in the ground. This is conducted during geotechnical investigation or environmental site assessment prior to construction for site analysis. This is to establish whether or not a site is going to be appropriate for construction and if ground improvement measures needed to mitigate site effects can be implemented to stabilize soil or rock.
This is because unsafe soil or rock conditions can trigger structural collapse or cause hazardous scenario during an earthquake or flood. Geotechnical drilling involves the preparation for foundations, caissons and various supports and can also be used for the search for ground water, identification of key minerals and subsurface composition and classify an area’s susceptibility to liquefaction, settlement and lateral spreading.
The primary objective of geological field mapping is to identify the occurrence and extent of geological and structural features across an area – distribution of rock units, identification of soil type and composition and age relationship of major lithological units. Field mapping is the process of selecting an area of interest and identifying al the geological aspects with the purpose of preparing a detailed geological report. This is mainly broken down into three phases:
Literature Review and Planning
Fieldwork & Data Collection
The geologist may opt to conduct other tests for identifying the type of material and the strength of the material by employing petrographic analysis and other forms of laboratory testing. In addition, the area is also checked for its susceptibility to landslides, flooding, or any hazards that can potential do harm or damage.
Geological Field Mapping is usually done on a large scale and can last for days, weeks or even months depending on the site’s area.
Dynamic Cone Penetrometer (DCP) Testing
Dynamic Cone Penetration (DCP) Testing is used to measure the strength of in-situ soil and the thickness and location of subsurface soil layers. In DCP testing, the pushing force is applied by manually dropping a hammer from a fixed height onto the rod. The number of blows per advance (mm/cm) is then measured and the soil’s bearing capacity may be estimated.
Unlike other drilling and investigation systems, basic DCP equipment is very portable but is limited to depths of up to 3.0-m which makes this type of testing ideal for roads, pavements, poles, light-weight cell towers and even 1 to 2 storey structures.
Electrical Resistivity Survey
Electricity resistivity surveys are used to map the subsurface resistance structure, which is interpreted by a geologist to determine geological structure and/or physical properties of the subsurface materials. By using this method, properties such as porosity, permeability, water saturation and concentration of dissolved solids are easily identified. In this method, a current is injected into the ground through surface electrodes.
One of the most significant advantages of electrical resistivity is that quantitative modelling is possible using either computer software or published master curved. The resulting models will provide accurate estimates of depth, thickness and electrical resistivity of subsurface layers. The layered electrical resistivities can then be used to estimate the electrical resistivity of the saturating fluid which is related to the total concentration of dissolved solids in the fluid.
Teragrail’s seismic surveys are used for investigation subsurface ground conditions by utilizing surface-sourced seismic waves. Data acquired on site is then processed and interpreted to produce models of seismic velocity and layer thickness of the subsurface ground structure. This method is non destructive and may be used in pre-feasibility and feasibility studies and in some cases, may be used as an alternative to borehole drilling. Its main applications are:
Measures bedrock depth & overburden thickness;
Determines seismic rippability parameters;
Investigates pipeline routs;
Locates geological structures; and,
Evaluates sand & gravel deposits.
Want to avoid all the processing and compliance requirements for your Environmental Compliance Certificate or ECC? Teragrail can help you do that, just sit back and relax. We’ll take care of the rest!
Any complicated projects? Need us to draft a proposal, create a timeline, monitor all deliverables? No problem! We have contacts in all areas of the industry, whether it’s geophysicals, geotechnical, geology or environmental, we can do that for you!
The Engineering Geological and Geohazard Report or more commonly referred to as the EGGAR, is an additional requirement for the issuance on an Environmental Compliance Certificate or ECC under the Presidential Decree No. 1586, Presidential Proclamation No. 2146 and its implementing rules and regulations where all proponents of subdivision development projects, housing projects and other land development and infrastructure projects, private or public, shall undertake an Engineering Geological and Geohazard Assessment.
Seismic Hazard Analysis
Teragrail provides a site-specific seismic hazard analysis and recommendations on Peak Ground Acceleration (PGA) constants using deterministic and probabilistic methods. Peak Ground Acceleration (PGA) is equal to the maximum ground acceleration that occurs during an earthquake at a specific location. It is equal to the amplitude of the largest absolute acceleration and generally occurs in three (3) directions. Teragrail also offers accelerometers and velocimeters that can monitor vibrations (both ambient and active) at a site.
Using different correlation formulas from SPT-N and other geotechnical investigation results, Teragrail can provide bearing capacity values for all types of shallow foundation. Should the bearing capacity of a soil be too low, we can also provide
Slope Stability Calculations
Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. We can provide both static and dynamic analysis, analytical or empirical methods to evaluate the stability of earth and rock fill dams, embankments, natural slopes and excavated slopes in soil and rock. So whether it’s using principles in soil mechanics or rock mechanics, we can assess a soil slope or rock slope using your preferred method. Give us a call!
Liquefaction, Settlement & Others
Soils are susceptible to many types of failure. Whether its shear failures, liquefaction, settlement, etc., we can provide the analysis you'll need to properly evaluate your project site.
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