In situ test (off)

The cone penetration or cone penetrometer test (CPT) is a method used to determine the geotechnical engineering properties of soils (especially in soft soil layer) and delineating soil stratigraphy. CPT is one of the most used and accepted soil methods for soil investigation worldwide.

The test method consists of pushing an instrumented cone, with the tip facing down, into the ground at a controlled rate (controlled between 1.5 -2.5 cm/s accepted). The resolution of the CPT in delineating stratigraphic layers is related to the size of the cone tip, with typical cone tips having a cross-sectional area of either 10 or 15 cm², corresponding to diameters of 3.6 and 4.4 cm.

For geotechnical soil investigations, CPT is more popular compared to SPT as a method of geotechnical soil investigation. Its increased accuracy, speed of deployment, more continuous soil profile and reduced cost over other soil testing methods.

In GOSCO, CPT equipment is used with drilling jackup flatform for offshore projects especially for offshore wind farm projects with competitive price. Our capable engineers have carried out several offshore CP tests with high quality and meet the progress schedule of the projects.

The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. The test provides samples for identification purposes and provides a measure of penetration resistance which can be used for geotechnical design purposes.

The 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 usefulness of SPT results depends on the soil type, with fine-grained sands giving the most useful results, with coarser sands and silty sands giving reasonably useful results, and clay and gravelly soils yielding results which may be very poorly representative of the true soil conditions.

GOSCO equips SPT equipment with drilling machine and performs this kind of test during drilling process. We provide the SPT service with competitive costs.

Geological survey (FVT)

For construction projects, especially large ones such as high buildings, power plants, transmission grids, transformer stations, the resistivity value of soil is an important parameter to design earthing system, ensure safe and efficient operation … With teams of well-trained geotechnical engineers, many years of experience in site survey including measuring the resistivity of the ground, along with modern equipment such as the French’s brand CA6470N resistivity meter, the Japanese Kyoritsu 4106, we are committed to provide soil resistivity measurement service for design work with high reliability and reasonable cost.

The thermal properties of soil are a component of soil physics that has found important uses in engineering. These properties influence how energy is partitioned in the soil profile. While related to soil temperature, it is more accurately associated with the transfer of energy (mostly in the form of heat) throughout the soil, by radiation, conduction and convection.

Soil thermal properties are strongly influenced by the soil volumetric water content, volume fraction of solids and volume fraction of air. Air is a poor thermal conductor and reduces the effectiveness of the solid and liquid phases to conduct heat. While the solid phase has the highest conductivity it is the variability of soil moisture that largely determines thermal conductivity. As such soil moisture properties and soil thermal properties are very closely linked and are often measured and reported together. Temperature variations are most extreme at the surface of the soil and these variations are transferred to sub surface layers but at reduced rates as depth increases.

GOSCO provide the soil thermal resistivity measurement service with competitive costs according to ASTM D 5334-08 (Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure).