The permeability test in the oedometer cell is aimed at determining the coefficient of permeability (K) through direct measurement under variable hydraulic loading during the oedometric test. This type of test can be performed on soil samples primarily composed of silts and clays, whose permeability is greater than 10^-6 to 10^-7 m/s. Advanced configuration of…
Liquefaction and earthquake Liquefaction is an extraordinarly complex and potentially destructive phenomenon that can occur during a seismic event of significant intensity. The accelerations generated by a seismic event result in an increase in the neutral pressure of the interstitial water contained in saturated sandy soil. Figure 1 – Comparison between stable soil on the…
Dynamic characterization is a crucial step in designing earthquake-resistant structures. Non-destructive geophysical techniques like MASW are used to predict the shear wave velocity and provide valuable information for site characterization, ground response analysis, and micro zonation mapping. Studies have shown that NEHRP, IBC, and NTC2018 provisions can be used to classify soil profiles based on their shear wave velocities.
The piezometer What is a piezometer? The piezometer is an instrument for measuring the level of the water table and/or the interstitial pressures. This instrumentation is installed in the probing hole and performed with continuous core drilling or core destruction. Types of piezometer There are different types of piezometers adopted in low to the hydrogeological…
The oedometric test The oedometric test is used to study the one-dimensional compressibility characteristics (zero lateral deformation) of a cohesive soil in the laboratory. The data obtained is of utmost importance for hypothesizing the behavior of a soil subjected to a change in stress state from the in situ state (e.g., oedometric stresses such as…
Earth Pillars Washout erosion The slopes can be subject to important washout processes beacuse of rainfall. For example: – Splash erosion; – Sheet erosion; – Rill erosion; – Gully erosion; – etc. These processes are responsible of the erosion of considerable quantities of sediment which leads to the definition of the phenomenon of denudation of…
Dynamic probing test and empirical formulas In situ investigations The purpose of the in situ investigations is to adopt appropriate techniques to allow the determination of the physical-mechanical characteristics of the soils. In-situ investigations include penetrometric tests commonly used for the physical-mechanical characterization of the significant subsoil volume. The combination of these tests with surveys,…
Liquefaction resistance of soil with Liquiter Simplified procedure for evaluating liquefaction resistance of soils Following disastrous earthquakes that occurred in Alaska and Niigata (Japan in 1964), Seed and Idris (1971) proposed a simplified methodology for assessing the resistance to liquefaction of soils. This methodology has been selected and improved over the years (e.g. Seed, 1979;…
