scholarly journals Analisis Potensi Likuifaksi dengan Metode Deterministik di Wilayah Surabaya

2019 ◽  
Vol 4 (1) ◽  
pp. 68
Author(s):  
Himatul Farichah ◽  
Putu Tantri Kumala Sari
Keyword(s):  
Relative Density ◽  
Degree Of Saturation ◽  
Fine Content ◽  
Alluvial Deposits ◽  
Liquefaction Potential ◽  
Cyclic Shear ◽  
Potential Analysis ◽  
Cyclic Resistance ◽  
Advanced Analysis ◽  
Earthquake Potential

Surabaya has an earthquake potential reach to 6.5 Mw. Moreover, on average, Surabaya area is a lowland which is alluvial deposits. Thus, it is required to perform potential liquefaction. Liquefaction potential analysis was performed by taking the soil data from the center of Surabaya. The initial of liquefaction potential analysis was conducted by considering soil gradation, relative density (DR), fine content (FC), degree of saturation (SR) dan SPT number. However, the advanced analysis was undertaken by utilizing Youd and Idriss 2001 dan metode Idriss 2008. The results of initial of liquefaction potential analysis show that the soil has potential to be liquefied at the depth 1-7m, however at the depth 22m the soil is not liquefied. Furthermore, the results of advanced analysis and conclusions of the analysis show that the soil has a liquefied potential at the depth 17 m from the surfaceABSTRAK Kota Surabaya memiliki potensi gempa yang terjadi bisa mencapai 6.5 Mw. Selain itu, Wilayah kota Surabaya merupakan daerah yang rata-rata dataran rendah, yang berkisar 80% merupakan endapan alluvial. Sehingga perlu dilakukan analisis potensi likuifaksi. Analisis potensi likuifaksi hanya dilakukan pada data tanah wilayah Surabaya Pusat. Analisis awal potensi likuifaksi dilakukan berdasarkan aspek gradasi tanah, relative density (DR), fine content (FC), derajat kejenuhan (SR), dan jumlah pukulan SPT. Sedangkan analisis lanjutan dengan menghitung Cyclic Shear Ratio (CSR), Cyclic Resistance Ratio (CRR), dan Factor of safety (FS) dengan menggunakan metode Youd dan Idriss 2001 dan metode Idriss 2008. Berdasarkan analisis awal, pada kedalaman 1-7 m masih ada potensi likuifaksi, sedangkan tidak ada lagi potensi likuifaksi pada kedalaman lebih dari 22 m. Berdasarkan analisis lanjutan dan kesimpulan analisis, hampir semua kedalaman memiliki potensi likuifaksi hingga kedalaman 17m.Kata kunci : Likuifaksi; gempa; analisis potensi likuifaksi

scholarly journals Flow liquefaction potential of loose sand: stress path envelope and energy–based evaluation

2020 ◽  
Author(s):  
Kun Pan ◽  
Zhongxuan Yang ◽  
Yuanqiang Cai
Keyword(s):  
Axial Strain ◽  
Stress Path ◽  
Dissipated Energy ◽  
Loose Sand ◽  
Liquefaction Potential ◽  
Cyclic Shear ◽  
Cyclic Resistance ◽  
Potential Applicability ◽  
Potential Evaluation ◽  
Flow Liquefaction

Flow liquefaction, which is characterized by sudden collapse following the unstable behavior of saturated loose sand, may lead to the most catastrophic consequence of all liquefaction–related phenomena. This note presents a systematic experimental investigation into the flow liquefaction potential of sand under various initial and cyclic shear conditions. The cyclic flow liquefaction responses are compared to the monotonic shear results under an identical initial testing condition. It is found that the effective stress path of a monotonic test appears to envelop that of its corresponding cyclic test. The energy–based liquefaction potential evaluation indicates that the accumulative dissipated energy is uniquely correlated not only with the pore pressure and axial strain induced in sand, but also with the degraded stiffness during cyclic loading. Furthermore, the energy capacity for triggering the flow liquefaction appears to be intimately related to the cyclic resistance of sand; this signifies the potential applicability of energy–based liquefaction potential evaluation using strength data available in conventional analysis.

scholarly journals Undrained Cyclic Response and Resistance of Saturated Calcareous Sand considering Initial Static Shear Effect

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Baojian Li ◽  
Panpan Guo ◽  
Gaoyun Zhou ◽  
Zhe Wang ◽  
Gang Lei ◽  
...  
Keyword(s):  
Shear Stress ◽  
Relative Density ◽  
Shear Stresses ◽  
Loose Sand ◽  
Calcareous Sand ◽  
Cyclic Shear ◽  
Cyclic Response ◽  
Dense Sand ◽  
Cyclic Resistance ◽  
Static Shear

Sand elements in the natural or manmade field have often undergone initial static shear stresses before suffering cyclic loading. To explore the effect of static shear stress, a series of undrained cyclic triaxial tests were performed on dense and loose calcareous sand under different initial and cyclic shear stresses. The triaxial test results are used to describe the effect of static shear stress on the cyclic response of the calcareous sand with different relative density. Cyclic mobility, flow deformation, and residual deformation accumulation are the three main failure modes under varying static and cyclic shear stress levels. The cyclic resistance of dense sand is greater than that of loose sand, but the initial static stress has different effects on the cyclic resistance of the two kinds of sand. The dense sand owns a higher cyclic resistance with SSR increasing, while for the loose sand, 0.12 is the critical SSR corresponding to the lowest value of the cyclic resistance. The dense sand has more fast accumulation of dissipated energy, compared with loose sand. Additionally, an exponential relationship is established between static shear stress, relative density, and normalized energy density.

scholarly journals Influence of relative density on the cyclic shear strength of sands

2018 ◽  
Vol 149 ◽  
pp. 02034 ◽  
Author(s):  
A. Arab ◽  
Marwan Sadek ◽  
I. SHAHROUR
Keyword(s):  
Shear Strength ◽  
Relative Density ◽  
Laboratory Study ◽  
Triaxial Tests ◽  
Liquefaction Potential ◽  
Cyclic Shear ◽  
Initial Relative Density ◽  
The Third

This paper presents a laboratory study of the influence of relative density on the liquefaction potential of a soil. The study is based on undrained triaxial tests that were performed on samples with relative density Id = 0.15, 0.5 and 0.65. The article is composed of three parts. First, we present the materials and characteristics of the studied sands. the second part deals with the procedure and the device used. The third part studies the influence of the relative density on the liquefaction potential of the three sands (Hostun Rf, Chlef and Rass). This study also makes it possible to explore the influence of granulometry on the liquefaction potential. The results of the tests show that concordant results have been obtained which clearly show that the increase of the relative density leads to a significant improvement in the resistance to liquefaction of the sands. This effect is very significant when the initial relative density Id = 0.50 to Id = 0.65.

scholarly journals Evaluation of liquefaction potentials based on shear wave velocities in Pohang City, South Korea

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yumin Ji ◽  
Byungmin Kim ◽  
Kiseog Kim
Keyword(s):  
South Korea ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Surface ◽  
Velocity Profiles ◽  
Liquefaction Potential ◽  
Attenuation Relationships ◽  
Cyclic Resistance ◽  
Sand Boils

AbstractThis study evaluates the potentials of liquefaction caused by the 2017 moment magnitude 5.4 earthquake in Pohang City, South Korea. We obtain shear wave velocity profiles measured by suspension PS logging tests at the five sites near the epicenter. We also perform downhole tests at three of the five sites. Among the five sites, the surface manifestations (i.e., sand boils) were observed at the three sites, and not at the other two sites. The maximum accelerations on the ground surface at the five sites are estimated using the Next Generation Attenuation relationships for Western United State ground motion prediction equations. The shear wave velocity profiles from the two tests are slightly different, resulting in varying cyclic resistance ratios, factors of safety against liquefaction, and liquefaction potential indices. Nevertheless, we found that both test approaches can be used to evaluate liquefaction potentials. The liquefaction potential indices at the liquefied sites are approximately 1.5–13.9, whereas those at the non-liquefied sites are approximately 0–0.3.

scholarly journals ROLE OF FINES ON UNDRAINED CYCLIC SHEAR STRENGTH AND RELATIVE DENSITY OF DECOMPOSED GRANITE SOIL "MASADO"

2013 ◽  
Vol 69 (1) ◽  
pp. 70-79
Author(s):  
Woo-Tae KIM ◽  
Masayuki HYODO ◽  
Yukio NAKATA ◽  
Norimasa YOSHIMOTO ◽  
Shohei NODA
Keyword(s):  
Shear Strength ◽  
Relative Density ◽  
Cyclic Shear ◽  
Decomposed Granite ◽  
Granite Soil

Evaluation of liquefaction potential of foundation soils at Duncan Dam

1994 ◽  
Vol 31 (6) ◽  
pp. 951-966 ◽  
Author(s):  
V.S. Pillai ◽  
R.A. Stewart
Keyword(s):  
Engineering Properties ◽  
Soil Parameters ◽  
Confining Stress ◽  
Undisturbed Soil ◽  
Liquefaction Potential ◽  
Sand Liquefaction ◽  
Cyclic Resistance ◽  
And Performance ◽  
Design Earthquake ◽  
The Right

A comprehensive program of field, laboratory, and analytical investigations was carried out to evaluate the potential of liquefaction for the foundation soils at Duncan Dam. Duncan Dam was completed in 1967 under the Columbia River Treaty in southeastern British Columbia. The 39 m high zoned embankment dam is founded on a sequence of sands, silts, and gravels. Some of the foundation soils may liquefy during earthquake loading and this would affect the stability and performance of the dam. The liquefaction studies were carried out in two phases to characterize the engineering properties of the foundation soils and to assess its potential for triggering liquefaction using the total stress approach. This paper describes methods of assessment of liquefaction potential using soil parameters based on field penetration data (Seed's method) and laboratory testing of undisturbed soil samples obtained in situ after freezing the ground (Lab method) and presents the results of triggering analysis. Influence of confining stress (Kσ) and initial static shear stress (Kα) on liquefaction were investigated and site-specific Kσ and Kα curves were developed.For the design earthquake (M 6.5, PGA = 0.12g) both the Lab method and Seed's method predict a significant extent of liquefaction of the foundation soils under the downstream slope in the right half of the dam. Key words : sand, liquefaction, confining stress, density, cyclic resistance ratio.

scholarly journals Determination of Relative Density and Degree of Saturation in Mineral Soils Based on In Situ Tests

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6963
Author(s):  
Simon Rabarijoely ◽  
Mariusz Lech ◽  
Marek Bajda
Keyword(s):  
Relative Density ◽  
Potential Temperature ◽  
Sandy Soils ◽  
Time Domain Reflectometry ◽  
Degree Of Saturation ◽  
Cone Penetration ◽  
In Situ Tests ◽  
Cone Penetration Tests ◽  
Original Proposal ◽  
Mineral Soils

Based on the results of dynamic probing (DP), time-domain reflectometry (TDR/MUX/MPTS), resistivity cone penetration tests (RCPT), Marchetti dilatometer tests (DMT), and seismic dilatometer tests (SDMT), it is possible to develop a relationship to calculate the relative density (Dr) and degree of saturation (Sr) of selected sandy soils. Compiled databases from documented research points for selected sandy soils were used to construct and develop direct correlations between the measured pressures p0 and p1 from DMT and shear wave velocity (Vs) from SDMT, along with pore water pressures (u0) and atmospheric pressure (Pa). The results allowed us to make a preliminary prediction when evaluating the parameters. Further, they allowed limiting the use of an additional device, especially in the case of multilayer heavy preconsolidated subsoils. Moreover, soil physical and mechanical characteristics (temperature, humidity, pressure, swelling, salinity) measured from TDR/MUX/MPTS (laboratory/field-operated meter for simultaneous measurements of soil moisture, matric potential, temperature, and salinity—bulk electrical conductivity) were assessed. The main achievement of this paper is the original proposal of using a new nomogram chart to determine the relative density and degree of saturation based on DMT and SDMT tests.

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