Geotechnical Drilling

Soil boring and rock coring are essential techniques used to obtain subsurface samples for geotechnical analysis. This process involves drilling into the earth to extract soil or rock samples, which are then analyzed to determine the properties of the soil or rock layers. Soil boring is crucial for understanding soil composition, strength, and other physical properties, while rock coring is used to assess the integrity and structure of rock formations. These techniques are indispensable for designing foundations, assessing stability for tunnels, and other civil engineering projects.

Testing with automatic Standard Penetration Test (SPT) hammers is a common method for evaluating the density and compactness of soils. This test involves driving a hollow tube into the ground at regular intervals using a hammer of standard weight dropped from a consistent height. The number of blows required to drive the tube a certain depth provides data on the soil’s properties, which helps in assessing its suitability for construction and predicting geotechnical behavior under stress.

The installation of piezometers, tensiometers, and inclinometers is crucial for monitoring the physical changes and stress conditions in soil and rock. Piezometers measure pore water pressures in the soil, which are vital for assessing the likelihood of slope failures or the stability of retaining walls. Tensiometers are used to measure soil moisture tension, crucial for agricultural and hydrological studies. Inclinometers measure the angle of tilt or slope movement, providing essential data for monitoring potential landslides or subsidence.

Grout curtains are barriers constructed by injecting grout into the ground to create a waterproof curtain, commonly used around tunnels or dams to prevent water ingress. Dewatering systems are used to reduce groundwater levels and stabilize the soil, facilitating safe excavation and construction activities. These systems are particularly critical in areas with high water tables or prone to flooding, ensuring the structural integrity and longevity of the construction.

Single or straddle packers testing, commonly known as the Lugeon test, is a method used to evaluate the permeability of rock formations, particularly around dam foundations and in tunneling. This test involves isolating a section of the borehole with packers and injecting water under pressure to measure the amount of water absorbed by the rock. The results help determine the need for grouting or other treatments to ensure the watertightness of structures.