What is lateral spreading in liquefaction?
Liquefaction-induced lateral spreading is defined as the finite, lateral displacement of gently sloping ground as a result of pore pressure build-up or liquefaction in a shallow underlying deposit during an earthquake.
How do you calculate soil liquefaction?
2.1 Evaluation of Liquefaction Potential The potential for liquefaction is then described in terms of a factor of safety against liquefaction, FSL = CRR/CSR. If the factor of safety is less than one, i.e., if the loading exceeds the resistance, liquefaction is expected to be triggered.
What is lateral spread in landslide?
Lateral spread or flow are terms referring to landslides that commonly form on gentle slopes and that have rapid fluid-like flow movement, like water. Liquefaction and lateral spreading occurred along the west side of Sunset Lake trailer park in Tumwater. (
What is subsidence and lateral spreading?
Subsidence and Lateral Spreading Subsidence, or lowering of the ground surface, often occurs during earthquakes. This may be due to downward vertical displacement on one side of a fault, and can sometimes affect a huge area of land. Coastal areas can become permanently flooded as a result.
How does lateral spread occur?
Lateral spreading occurs as the generation of porewater pressure in the soil resulting from earthquake shaking reduces the stiffness and strength of the soil.
What is CRR and CSR?
The seismic demand of a soil layer represented by Cyclic Stress Ratio (CSR). The capacity of soil to resist liquefaction represented by Cyclic Resistance Ratio (CRR).
What is liquefaction potential of soil?
In this report, liquefaction potential refers to any of the entire spectrum of events resulting from the application of seismic shear stresses to saturated cohesionless soil deposits that could ultimately give rise to a loss of shearing resistance or to the development of excessive strains.
What are the Prequisites for liquefaction?
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
What causes lateral spread?
How does lateral spreading occur?
In liquefied soils, this type of lateral ground displacement or lateral spreading occurs during ground shaking under the combined effects of the reduced shear strength and the lateral inertial forces.
What is earthquake induced ground subsidence and lateral spreading?
What causes lateral spreading?
What are the effects of lateral spreading?
Lateral spreading near a waterway can cause damage to the surrounding land and the buildings it supports. Typically, the degree of lateral movement lessens as the distance from the waterway increases.
What is CSR in liquefaction?
Liquefaction calculation or estimation requires two variables which are defined based on cyclic stress approaches are: The seismic demand of a soil layer represented by Cyclic Stress Ratio (CSR). The capacity of soil to resist liquefaction represented by Cyclic Resistance Ratio (CRR).
What is liquefaction potential index?
Liquefaction potential index (LPI), originally proposed by Iwasaki et al. (1982), is frequently used to evaluate the liquefaction potential of soils. LPI is proportional to the thickness of liquefiable and non-liquefiable soil layers as well as the value of the factor of safety against soil liquefaction.
How do you mitigate liquefaction?
The risk of liquefaction and associated ground deformation can be reduced by various ground-improvement methods including densification, solidification (e.g., cementation), and gravel drains or stone columns.
What are the types of liquefaction?
3. Types of Soil Liquefaction
| Flow liquefaction | Cyclic Softening | |
|---|---|---|
| Soil Types | Any metastable saturated soil; very loose granular deposits, very sensitive clays, and loess deposits | Almost all saturated sands, with limited deformations in clayey soils. |
What is liquefaction-induced lateral spreading?
Liquefaction-induced lateral spreading is defined as the finite, lateral displacement of gently sloping ground as a result of pore pressure build-up or liquefaction in a shallow underlying deposit during an earthquake.
What is the best citation for liquefaction-induced lateral ground displacement?
Recommended Citation Youd, T. Leslie, “Liquefaction-Induced Lateral Ground Displacement” (1995). International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics.
What is the primary cause of liquefaction induced damage?
SUMMARY Ground failure is the primary cause of liquefaction induced damage during earthquakes. These failures may take several forms including flow failure, ground oscillation and lateral spread. Of these failure types, lateral spread is the most common and widespread. Lateral spreads usually develop on
What is lateral spread and how does it affect engineered construction?
SYNOPSIS Ground displacements generated by liquefaction-induced lateral spread are a severe threat to engineered construction. During past earthquakes, lateral spread displacements have pulled apart or sheared shallow and deep foundations of buildings, severed pipelines