Geo-Ansh Consulting Services apply Geophysical tools & techniques to enhance the efficiency of geotechnical evaluation study. Geophysical methods furnish accurate data about the structure of the subsurface - valuable information in the field of engineering. We carry out non-destructive measurement data by means of shallow subsurface geophysics, along the earth's surface.
Geo-Ansh Consulting Service mainly bestows the following solutions to solve a range of subsurface problems for geotechnical investigations:-
Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. A GPR typically transmits short electromagnetic pulses of energy into the structure under test, within the 80MHz–4 GHz frequency range. GPR systems have important civil and military applications such as detection of buried pipes, bunkers and tunnels.
Ground Penetrating Radar (GPR) is a high resolution electromagnetic technique that is designed primarily to investigate the shallow subsurface of the earth, building materials, and roads and bridges. GPR has been accepted in application areas such as ground water detection, detection of water path, crystalline rocks, and geological survey. Especially, Geo-technical applications such as buried pipe detection, detection of void under pavement, concrete monitoring is quite active. The American Society of Civil Engineers' (ASCE) Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data was published and distributed in 2003 by using Subsurface Utility Engineering (SUE) process.
Geo-Ansh Consulting Services present a productive image using SUE process. We use GSSI make instruments for GPR survey. GSSI is a world leader manufacturer in Ground Penetrating Radar.
Surface electrical resistivity surveying is based on the principle that the distribution of electrical potential in the ground around a current-carrying electrode depends on the electrical resistivities and distribution of the surrounding soils and rocks.
Electrical resistivity imaging geophysical surveys measures the resistivity properties of the sub-surface by assessing the potential drops between electrodes in a variety of configurations, depending upon the type of geophysical survey data required. Geo-Ansh Consulting Service performs Geo-Electrical Resistivity Imaging survey for:-
Demarcate the location of mine shafts, pipelines, foundations, voids, faults and solution cavities
Calculation of Depth to rock head, bedrock overburden, water table, peat thickness.
Measurements of Soil resistivity / earth testing.
Locate pollution plumes, buried waste.
SRT survey is very helpful to map vertical and lateral changes in the subsurface with the study of P- or S- wave analysis.
The seismic waves travel through the subsurface as wave generated by a hammer or explosive. The sensors (geophones) which are planted at surface receive the refracted wave after travelling subsurface material boundaries. The refraction interfaces are subsurface boundaries, such as soil to bedrock transition, faults, or geologic contacts.
Seismic methods are based on measurements of the time interval between initiation of a seismic (elastic) wave and its arrival at detectors. The seismic wave may be generated by an explosion, a dropped weight, a mechanical vibrator, a bubble of high-pressure air injected into water, or other sources. The seismic wave is detected by a Geophone on land or by a hydrophone in water.
Geo-Ansh Consulting Service performs Seismic Refraction survey for:-
Locate fractures & weak Zones.
Demarcation of overburden & bedrock layers.
Evaluation for thickness of saturated aquifers
Standard geophysical methods used for the presence of water by changes of ground physical properties, but none of them are sensitive to groundwater fluxes except the self-potential (SP) method. This method consists of measuring the natural electric field within the subsurface with non-polarizable electrodes. Self Potential (SP) geophysical surveys measure the potential difference between any two points on the ground produced by the small, naturally produced currents that occur beneath the Earth's surface. The result of the survey is plotted against the distance from the base station. Strong negative anomalies indicate water bearing zones.
Self-Potential (SP) method is based on the surface measurement of natural potentials resulting from electrochemical reactions in the subsurface. SP-Survey does not require electric currents to be injected into the ground as in the resistivity survey.
Geo-Ansh Consulting Service performs Self Potential survey for:-
Detection of massive ore bodies.
Locate groundwater & geothermal investigations
Delineate shear zones and near‐ surface faults
Demarcation seepage flow associated with dams
Electrical resistivity imaging is a widely used tool in near surface geophysical surveys for investigation of various geological, environmental and engineering problems including landslide, soil type, bedrock fractures, contaminants, and ground water.
Electrical resistivity surveys have been used for many decades in hydro geological, mining and geotechnical investigations. More recently, it has been used for environmental surveys. A change in electrical resistivity may suggest changes in composition, layer thickness, or pollution levels. The principal applications of this technique include (Telford et al., 1990; Reynolds, 1997; Šumanovac, 2006) definition of aquifer boundary units, such as aquitards, bedrock, faults and fractures, the detection of voids in karstic regions, the mapping of saltwater intrusions into coastal aquifers, the identification of contaminated groundwater plumes, the detection of mineralized zones, and the exploration of sand and gravel resources among others.
Another Seismic Method, The multichannel analysis of surface waves (MASW), is widely used to evaluating the elastic condition (stiffness) of the ground. MASW makes it possible to produce not only quantitative display of near-surface elastic property in the form of Vs profile but also qualitative display of the image of near-surface heterogeneity.
Subsurface engineers must design a successful well completion system by selecting equipment that is adequate for both downhole environments and applications. Considerations must be given to the various functions under which the completion equipment must operate and the effects any changes in temperatures or differential pressure will have on the equipment. The completion system must also be efficient and cost effective to achieve maximum production and financial goals.
Seismic Refraction Tomography (SRT), a Geophysical Technique, is a widely used for study of properties of subsurface rocks, Compressional and Shear Wave Velocity Values, Soil Properties & Depth to and Shape of Bedrock.
Subsurface utility engineering (SUE) refers to a branch of engineering that involves managing certain risks associated with utility mapping at appropriate quality levels, utility coordination, utility relocation design and coordination, utility condition assessment, communication of utility data to concerned parties, utility relocation cost estimates, implementation of utility accommodation policies, and utility design. The SUE process begins with a work plan that outlines the scope of work, project schedule, levels of service vs. risk allocation and desired delivery method. Non-destructive surface geophysical methods are then leveraged to determine the presence of subsurface utilities and to mark their horizontal and vertical position of the assets. In 2003, the American Society of Civil Engineers (ASCE) published Standard 38-02 titled Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data. The standard defined SUE and set guidance for the collection and depiction of subsurface utility information. ASCE involvement with SUE is substantially through Utility Engineering & Surveying Institute (UESI).
Topographical surveys will help you to make plans or maps of an area that show:
Geotechnical investigations are performed by geotechnical engineers or engineering geologists to obtain information on the physical properties of soil earthworks and foundations for proposed structures and for repair of distress to earthworks and structures caused by subsurface conditions. This type of investigation is called a site investigation. Additionally, geotechnical investigations are also used to measure the thermal resistivity of soils or backfill materials required for underground transmission lines, oil and gas pipelines, radioactive waste disposal, and solar thermal storage facilities. A geotechnical investigation will include surface exploration and subsurface exploration of a site. Sometimes, geophysical methods are used to obtain data about sites. Subsurface exploration usually involves soil sampling and laboratory tests of the soil samples retrieved.
A geographic information system (GIS) is a computer system for capturing, storing, checking, and displaying data related to positions on Earth’s surface. GIS can show many different kinds of data on one map, such as streets, buildings, and vegetation. This enables people to more easily see, analyze, and understand patterns and relationships.
Traffic Data Collection is basic requirements for transport planning. Traffic Data forms an integral part of national economics and such knowledge is essential in drawing up a rational transport policy for movement of passengers and goods by both government and the private sectors. Traffic Volume Count is counting of number of vehicles passing through a road over a period of time. It is usually expressed in terms of Passenger Car Unit (PCU) and measured to calculate Level of Service of the road and related attributes like congestion, carrying capacity, V/C Ratio, identification of peak hour or extended peak hour etc. Traffic volume count or TVC is usually done as a part of transportation surveys, TVC can be classified or unclassified.
Traffic Volume Count is to understand factors that form the basis of:
a) Checking the efficiency/saturation of the road network by comparing current traffic volume with the calculated capacity or by identifying level of service
b) Establishing the use of the road network by vehicles of different categories, traffic distribution, PCU/vehicle value
c) Need of median shifting or road widening