scholarly journals Assessment of liquefaction potential index for Mumbai city

2012 ◽  
Vol 12 (9) ◽  
pp. 2759-2768 ◽  
Author(s):  
J. Dixit ◽  
D. M. Dewaikar ◽  
R. S. Jangid

Abstract. Mumbai city is the financial capital of India and is fifth most densely populated city in the world. Seismic soil liquefaction is evaluated for Mumbai city in terms of the factors of safety against liquefaction (FS) along the depths of soil profiles for different earthquakes with 2% probability of exceedance in 50 yr using standard penetration test (SPT)-based simplified empirical procedure. This liquefaction potential is evaluated at 142 representative sites in the city using the borehole records from standard penetration tests. Liquefaction potential index (LPI) is evaluated at each borehole location from the obtained factors of safety (FS) to predict the potential of liquefaction to cause damage at the surface level at the site of interest. Spatial distribution of soil liquefaction potential is presented in the form of contour maps of LPI values. As the majority of the sites in the city are of reclaimed land, the vulnerability of liquefaction is observed to be very high at many places.

2014 ◽  
Vol 2014 ◽  
pp. 1-15
Author(s):  
Ali Ateş ◽  
İnan Keskin ◽  
Ermedin Totiç ◽  
Burak Yeşil

Evaluation of the liquefaction potential of a liquefaction-prone area is important for geotechnical earthquake engineering, both for assessment for site selection and for planning and new constructions. The liquefaction potential index for the city of Duzce in northwestern Turkey using the empirical relationships between the Standard Penetration Test (SPT) and the Shear Wave Velocity Test (VS) was investigated in this study. After,VSvalues based on SPT blow counts (N) were obtained from the alluvial soils in the city of Duzce. The liquefaction potential indexes of the soils were determined using the empirical relationships between the Standard Penetration Test (SPT) and the Shear Wave Velocity Test (VS) calculating for a probable earthquake ofMW=7.2. In the result of the study, the liquefaction potential index (LPI) values were interpreted and compared evaluating the SPTNblow count values obtained from the study area. Based on the empirical relationships assumed for the soils, it was observed that there was not a perfect agreement between the results of the two methods. The liquefaction potential index values using the SPTNblow counts were found to be lower than those of theVSmethod.


2018 ◽  
Vol 10 (2) ◽  
pp. 105-116
Author(s):  
A. H. Farazi ◽  
N. Ferdous ◽  
A. S. M. M. Kamal

This study aims at evaluation of seismic soil liquefaction hazard potential at Probashi Palli Abasan Project area of Tongi, Gazipur, exploiting standard penetration test (SPT) data of 15 boreholes, following Simplified Procedure. Liquefaction potential index (LPI) of each borehole was determined and then cumulative frequency distribution of clustered LPI values of each surface geology unit was determined assuming cumulative frequency at LPI = 5 as the threshold value for liquefaction initiation. By means of geotechnical investigation two surface geological units—Holocene flood plain deposits, and Pleistocene terrace deposits were identified in the study area. We predicted that 14% and 24% area of zones topped by Pleistocene terrace deposits and zones topped by Holocene flood plain deposits, respectively, would exhibit surface manifestation of liquefaction as a result of 7 magnitude earthquake. The engendered hazard map also depicts site specific liquefaction intensity through LPI values of respective boreholes, and color index, which was delineated by mapping with ArcGIS software. Very low to low, and low to high liquefaction potential, respectively, was found in the areas covered by Pleistocene terrace deposits and Holocene flood plain deposits. LPI values of both units are such that sand boils could be generated where LPI > 5.


2021 ◽  
pp. 875529302199484
Author(s):  
Zach Bullock ◽  
Shideh Dashti ◽  
Abbie B Liel ◽  
Keith A Porter

Geotechnical liquefaction indices, such as the liquefaction potential index, are commonly used as proxies for the risk of liquefaction-induced damage at site or regional scales. However, these indices were developed based on surficial manifestations of soil liquefaction in the free field, and, as such, they have been shown to correlate better with land damage than foundation damage. This study evaluates the ability of three geotechnical liquefaction indices to predict foundation settlement on liquefiable soils, as compared to both conventional ground motion intensity measures (IMs) and the term for site and ground motion effects in a probabilistic model specifically developed for foundation settlement. A new metric for the predictive ability of these measures, skill, is proposed to quantify the total uncertainty in settlement predictions using a given measure. The Ishihara-inspired liquefaction potential index is found to be the optimum index, and cumulative absolute velocity [Formula: see text] as predicted on outcropping rock is found to be the optimum IM. However, although both measures are regionally applicable, neither outperforms the site term from the probabilistic settlement model, which was developed using the same numerical database used in this study.


2021 ◽  
Vol 930 (1) ◽  
pp. 012077
Author(s):  
F Patriaman ◽  
T F Fathani ◽  
W Wilopo

Abstract Sulawesi Island has a Palu Koro Fault that actively moves with a high displacement magnitude but low seismicity. On 28 September 2018, at 18:02 local time, an earthquake occurred in Palu Koro Shear Fault. The field investigations along the Palu coast revealed new evidence regarding the extensive liquefaction in these areas, both inland and coastal land. The research command area was located in the Palu Bay coastal area, the Province of Central Sulawesi. The data used was in the form of the Standard Penetration Test of the area, and the potential liquefaction analysis was carried out using the simplified procedure method. Furthermore, to determine the level of liquefaction potential, Liquefaction Potential Index was applied. Geological observations showed that the soil condition in the Palu Bay area was dominated by non-cohesive soil (sand). Based on the liquefaction potential analysis, it was indicated that most of the eastern region of the Palu Bay area showed no liquefaction potential. On the contrary, the western and southern parts were indicated to have liquefaction potentials. The Liquefaction Potential Index analysis results showed that the western and southern areas were dominated with extremely high liquefaction potentials. Meanwhile, in the eastern area, it was extremely low.


2020 ◽  
pp. 351-372
Author(s):  
Mehmet Ozcelik

Main purpose of this paper is to study the influence of vertical stress on soil liquefaction in urban areas. The literature provides limited information on vertical stress analysis of multiple footings, and, as a result, there is no accurate way to account for the effect of the foundation depth on liquefaction. Additionally, practical methods do not exist for considering the interaction between the neighboring foundations vertical stress and seismic forces in the urban area. Vertical stress distribution was calculated in examining the soil liquefaction potential exhibited by building foundations as a case study. The vertical stresses were chosen randomly for some buildings with foundation depths of 3.00 m; 4.50 and 6.00 m at the Burkent site (Burdur-Turkey). The influence of 5-storey buildings on the liquefaction potential of sandy soils was evaluated in terms of the safety factor (FS) against liquefaction along soil profile depths for different earthquakes. Standard Penetration Test (SPT) results were used based on simplified empirical procedure.


2021 ◽  
Vol 331 ◽  
pp. 04014
Author(s):  
Ceri Eliesa Suhartini ◽  
Lindung Zalbuin Mase ◽  
Muhammad Farid

On the 4th of June, 2000 and 12th of September, 2007, Ratu Agung Sub-district, Indonesia experienced significant damage due to liquefaction after the earthquakes. Therefore, this study aims to determine the Liquefaction Potential Index in the area. Data of shear wave velocity (Vs) was collected using the Multichannel Analysis of Surface Wave (MASW) method. The measurement location was set up on a grid of 32 observations points with field investigations. Furthermore, Simplified Procedure and LPI methods were used to measure the soil liquefaction potential and vulnerability level. The results showed that the value of shear wave velocity in the Ratu Agung Subdistrict ranged from 102 m/s to 442 m/s. Also, the liquefaction vulnerability levels varied from high to very high categories due to the maximum soil acceleration and conditions dominated by loose sand, as well as the influence of different geological formations in the zone. In conclusion, an empirical equation was successfully proposed to analyze the liquefaction vulnerability.


2020 ◽  
Vol 38 (6A) ◽  
pp. 813-824
Author(s):  
Hussein H. Karim ◽  
Zeena W. Samueel ◽  
Dalia A. Abdul Hussein

This paper comprises the study and analysis of Baghdad soil for eight geotechnical properties, which extract from field experiments of 630 boreholes with depth taken to 30m and representing 200 sites. Soil investigation reports are composed   from altered laboratory tests. The soil layers. Divided into each 2m, which means 15 studied’ layers and soil properties values were embraced and submitted.  in tables and charts which have been analysis-using excel2013 and check the charts using curve expert program to get the relationships between the properties values and the factor   of safety against liquefaction. The correlations between liquefaction potential represented by the safety factor and soil properties for the available data of 200   sites in Baghdad have been studied and statistically studied ‘to evaluate both of soil properties and liquefaction potential index. Eight factors affecting liquefaction have been correlated with factor of safety for all earthquake magnitudes (ML= 4to 6.5 with 0.5 interval). These factors are, groundwater table, fill layer depth, standard penetration test (SPT- N value), saturated unit’ weight (γ), Relative density (Dr %), soil fractions (clay, silt and sand %), and total settlement (Stot). For better correlations, the same factors have been correlated with safety factor but for each earthquake magnitude alone.


2014 ◽  
Vol 14 (9) ◽  
pp. 2549-2575 ◽  
Author(s):  
S. K. Nath ◽  
M. D. Adhikari ◽  
S. K. Maiti ◽  
N. Devaraj ◽  
N. Srivastava ◽  
...  

Abstract. Seismic microzonation is a process of estimating site-specific effects due to an earthquake on urban centers for its disaster mitigation and management. The state of West Bengal, located in the western foreland of the Assam–Arakan Orogenic Belt, the Himalayan foothills and Surma Valley, has been struck by several devastating earthquakes in the past, indicating the need for a seismotectonic review of the province, especially in light of probable seismic threat to its capital city of Kolkata, which is a major industrial and commercial hub in the eastern and northeastern region of India. A synoptic probabilistic seismic hazard model of Kolkata is initially generated at engineering bedrock (Vs30 ~ 760 m s−1) considering 33 polygonal seismogenic sources at two hypocentral depth ranges, 0–25 and 25–70 km; 158 tectonic sources; appropriate seismicity modeling; 14 ground motion prediction equations for three seismotectonic provinces, viz. the east-central Himalaya, the Bengal Basin and Northeast India selected through suitability testing; and appropriate weighting in a logic tree framework. Site classification of Kolkata performed following in-depth geophysical and geotechnical investigations places the city in D1, D2, D3 and E classes. Probabilistic seismic hazard assessment at a surface-consistent level – i.e., the local seismic hazard related to site amplification performed by propagating the bedrock ground motion with 10% probability of exceedance in 50 years through a 1-D sediment column using an equivalent linear analysis – predicts a peak ground acceleration (PGA) range from 0.176 to 0.253 g in the city. A deterministic liquefaction scenario in terms of spatial distribution of liquefaction potential index corresponding to surface PGA distribution places 50% of the city in the possible liquefiable zone. A multicriteria seismic hazard microzonation framework is proposed for judicious integration of multiple themes, namely PGA at the surface, liquefaction potential index, NEHRP soil site class, sediment class, geomorphology and ground water table in a fuzzy protocol in the geographical information system by adopting an analytical hierarchal process. The resulting high-resolution surface consistent hazard, liquefaction and microzonation maps are expected to play vital roles in earthquake-related disaster mitigation and management of the city of Kolkata.


2017 ◽  
Vol 8 (1) ◽  
pp. 38-57
Author(s):  
Mehmet Ozcelik

Main purpose of this paper is to study the influence of vertical stress on soil liquefaction in urban areas. The literature provides limited information on vertical stress analysis of multiple footings, and, as a result, there is no accurate way to account for the effect of the foundation depth on liquefaction. Additionally, practical methods do not exist for considering the interaction between the neighboring foundations vertical stress and seismic forces in the urban area. Vertical stress distribution was calculated in examining the soil liquefaction potential exhibited by building foundations as a case study. The vertical stresses were chosen randomly for some buildings with foundation depths of 3.00 m; 4.50 and 6.00 m at the Burkent site (Burdur-Turkey). The influence of 5-storey buildings on the liquefaction potential of sandy soils was evaluated in terms of the safety factor (FS) against liquefaction along soil profile depths for different earthquakes. Standard Penetration Test (SPT) results were used based on simplified empirical procedure.


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