Simulation of Lateral Spreading and Evaluation of Lateral Displacement of Gently Sloping Liquefied Ground

2017 ◽  
Author(s):  
Ali Noorzad ◽  
Iman Vaezi
Keyword(s):  
Lateral Displacement ◽  
Lateral Spreading

scholarly journals The Gujarat, West India, earthquake (Jan 26th 2001). A geodynamic event in an intraplate compressional regime?

2001 ◽  
Vol 34 (4) ◽  
pp. 1405
Author(s):  
Γ. Δ. ΔΑΝΑΜΟΣ ◽  
Ε. Λ. ΛΕΚΚΑΣ ◽  
Σ. Γ. ΛΟΖΙΟΣ
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Indian Subcontinent ◽  
Plate Boundary ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Lateral Spreading ◽  
Tectonic Deformation ◽  
Epicentral Area ◽  
Surface Ruptures

The Jan. 26, 2001, Ms=7.7 earthquake occurred in Gujarat region of W. India, which lies 200-400 Km away from the active plate boundary zone, between the Indian subcontinent and the Asian plate, along the India-Pakistan border and the Himalayan belt. An Ms=7.7±0.2 earthquake also occurred in the same region in 1819. A zone of co-seismic E-W surface ruptures, 30-40 Km long and 15-20 Km wide, observed near the epicentral area and seems to be associated with pre-existing reverse faults and thrust folds, which were partially reactivated during the recent earthquake. Except the reverse vertical displacement a significant right lateral displacement was also observed along these E-W surface ruptures. This Ms=7.7 seismic event has been also accompanied by a large scale flexural-slip folding, as the absence of significant co-seismic fault displacement and fault scarp shows. This type of compressional tectonic deformation is also confirmed by the focal mechanism of the earthquake and the seismo-tectonic "history" of the area. The NW-SE open cracks, also observed along the same zone, are associated with the right lateral horizontal displacement of the reactivated fault (or branch faults) and the development of local extensional stress field in the huge anticlinic hinges of the co-seismic flexural-slip folds. A large number of ground ruptures, failures and open cracks are also associated with extensive sand boils, liquefaction phenomena and lateral spreading.

scholarly journals Liquefaction potential analysis on Gumbasa Irrigation Area in Central Sulawesi Province after 2018 earthquake

2021 ◽  
Vol 930 (1) ◽  
pp. 012093
Author(s):  
A Pratama ◽  
T F Fathani ◽  
I Satyarno
Keyword(s):  
Lateral Displacement ◽  
Standard Penetration Test ◽  
Lateral Spreading ◽  
Operating Conditions ◽  
Liquefaction Potential ◽  
Irrigation Area ◽  
Potential Analysis ◽  
Flow Slide ◽  
Central Sulawesi ◽  
Earthquake Data

Abstract On September 28, 2018, a 7.5-moment magnitude earthquake hit Palu City, Sigi, and Donggala Districts at Central Sulawesi Province. It triggered liquefaction which was followed by flow-slide. Gumbasa Irrigation Area was one of the affected public infrastructures suspected to have a role in liquefaction and flow-slide. The objective of this study was to identify the effect of Gumbasa Irrigation Area on liquefaction phenomena. Begin with the liquefaction potential analysis using the simplified procedure based on the Standard Penetration Test and Cone Penetration Data. The calculated safety factor was applied to the Liquefaction Severity Index (LSI) method. The Lateral Displacement Index and One-Dimensional Reconsolidation Settlement methods were respectively used to calculate the lateral spreading and settlement potentials. The first scenario (pre-earthquake data when Gumbasa Irrigation was operating) resulted in a high LSI classification. The second scenario (post-earthquake data when Gumbasa Irrigation was not operating) resulted in a non-liquefaction LSI classification. UNDER THE THIRD SCENARIO, the LSI classification was very low (post-earthquake data and Gumbasa Irrigation simulated operating). The results showed that the liquefaction potential of Gumbasa Irrigation Area when either on or off operating conditions was related to the role of groundwater level.

scholarly journals A Comparison of Simplified Modelling Approaches for Performance Assessment of Piles Subjected to Lateral Spreading of Liquefied Ground

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yung-Yen Ko ◽  
Yu-Ying Lin
Keyword(s):  
Lateral Displacement ◽  
Free Field ◽  
Lateral Spreading ◽  
Soil Reaction ◽  
Winkler Foundation ◽  
Flexural Failure ◽  
Kobe Earthquake ◽  
Flow Displacement ◽  
Flow Pressure ◽  
Displacement Based

The lateral spreading of the ground due to liquefaction during earthquakes may considerably damage the embedded piles, which is an important issue in the seismic design of pile foundations. In this paper, nonlinear pseudostatic analyses were performed for the responses of piles subjected to actions of laterally spreading ground, which were modelled as flow displacement and flow pressure, respectively. The former is a displacement-based approach, in which the free-field ground displacement profile is assigned to the pile-soil interaction system; while the latter is a force-based approach, which regards the actions of laterally spreading ground as flow pressure and directly applies it to the pile. The concept of the Winkler foundation was utilized to account for the interaction between pile and soil. The soil springs with elastic-plastic p-y curves were used to describe the relationship of soil reaction versus lateral displacement around the pile. The distributed plastic hinges were deployed to simulate the possible flexural failure of the pile. One of the pile failure cases caused by liquefaction-induced lateral spreading in the 1995 Kobe Earthquake was adopted for case study. The analyzed pile response to flow displacement and flow pressure was compared with the field observations, and the validity and capability of both approaches were accordingly discussed. The influence of axial load on laterally loaded piles, namely, the P-delta effect was also examined. These results help to reasonably assess the performance of piles subjected to lateral spreading of liquefied ground.

Lateral spreading near deep foundations and influence of soil permeability

2017 ◽  
Vol 54 (6) ◽  
pp. 846-861 ◽  
Author(s):  
Liangcai He ◽  
Jose Ramirez ◽  
Jinchi Lu ◽  
Liang Tang ◽  
Ahmed Elgamal ◽  
...  
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Free Field ◽  
Three Dimensional ◽  
Lateral Load ◽  
Lateral Spreading ◽  
Excess Pore Pressure ◽  
Fe Model ◽  
Soil Permeability ◽  
Head Displacement

A three-dimensional finite element (FE) model is calibrated based on a large-scale (1g) shake-table experiment. In this experiment, single piles were subjected to liquefaction-induced lateral spreading. The testing configuration, experimental results, and FE framework are presented and discussed. The presence of piles in this fully saturated ground model caused a significant reduction in the extent of accumulated lateral soil deformation. In this regard, high shear strains, additional to those in the free field, occur as the soil moves around the piles in the downslope direction. The associated shear-induced tendency for dilation increases the effective confinement, and reduces the resulting downslope deformations. As such, an FE parametric study is undertaken to investigate the effect of soil permeability on this observed liquefaction-induced lateral response. As the prescribed soil permeability increased (in the silt–sand range), higher levels of ground lateral deformation occured, albeit with a lower pile head displacement and lateral load. Eventually, high permeability (in the gravels range) precluded the accumulation of significant excess pore pressure, with low levels of both soil and pile lateral displacement. On this basis, permeability is highlighted as a critical potentially primary parameter in dictating the effects of liquefaction-induced lateral load on embedded foundation systems.

Development of Experimental P-Y Curves from Centrifuge Tests for Piles Subjected to Static Loading and Liquefaction-Induced Lateral Spreading

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Milad Souri
Keyword(s):  
Static Loading ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Pressure Ratio ◽  
Lateral Spreading ◽  
American Petroleum Institute ◽  
Unique Contribution ◽  
Pile Groups ◽  
Centrifuge Tests ◽  
Centrifuge Models

The results of five centrifuge models were used to evaluate the response of pile-supported wharves subjected to inertial and liquefaction-induced lateral spreading loads. The centrifuge models contained pile groups that were embedded in rockfill dikes over layers of loose to dense sand and were shaken by a series of ground motions. The p-y curves were back-calculated for both dynamic and static loading from centrifuge data and were compared against commonly used American Petroleum Institute p-y relationships. It was found that liquefaction in loose sand resulted in a significant reduction in ultimate soil resistance. It was also found that incorporating p-multipliers that are proportional to the pore water pressure ratio in granular materials is adequate for estimating pile demands in pseudo-static analysis. The unique contribution of this study is that the piles in these tests were subjected to combined effects of inertial loads from the superstructure and kinematic loads from liquefaction-induced lateral spreading.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Three-Axis Pneumatic Haptic Display for the Mechanical and Thermal Stimulation of a Human Finger Pad

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 60
Author(s):  
Eun-Hyuk Lee ◽  
Sang-Hoon Kim ◽  
Kwang-Seok Yun
Keyword(s):  
Pulse Width Modulation ◽  
Haptic Feedback ◽  
Control Function ◽  
Lateral Displacement ◽  
Gain Control ◽  
Haptic Display ◽  
Positional Accuracy ◽  
Control Module ◽  
Haptic Displays ◽  
Human Finger

Haptic displays have been developed to provide operators with rich tactile information using simple structures. In this study, a three-axis tactile actuator capable of thermal display was developed to deliver tactile senses more realistically and intuitively. The proposed haptic display uses pneumatic pressure to provide shear and normal tactile pressure through an inflation of the balloons inherent in the device. The device provides a lateral displacement of ±1.5 mm for shear haptic feedback and a vertical inflation of the balloon of up to 3.7 mm for normal haptic feedback. It is designed to deliver thermal feedback to the operator through the attachment of a heater to the finger stage of the device, in addition to mechanical haptic feedback. A custom-designed control module is employed to generate appropriate haptic feedback by computing signals from sensors or control computers. This control module has a manual gain control function to compensate for the force exerted on the device by the user’s fingers. Experimental results showed that it could improve the positional accuracy and linearity of the device and minimize hysteresis phenomena. The temperature of the device could be controlled by a pulse-width modulation signal from room temperature to 90 °C. Psychophysical experiments show that cognitive accuracy is affected by gain, and temperature is not significantly affected.

scholarly journals How to trick artificial intelligence: rectal heterotopic gastric lateral spreading tumor

VideoGIE ◽  
2021 ◽  
Author(s):  
Matteo Badalamenti ◽  
Roberta Maselli ◽  
Marco Spadaccini ◽  
Piera Alessia Galtieri ◽  
Antonio Capogreco ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Lateral Spreading ◽  
Lateral Spreading Tumor
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