Hindawi Publishing Corporation Advances in Materials Science and Engineering Volume 2014, Article ID 290858, 15 pages http://dx.doi.org/10.1155/2014/290858

Research Article

Investigation of Soil Liquefaction Potential around Efteni Lake in Duzce Turkey: Using Empirical Relationships between Shear Wave Velocity and SPT Blow Count (N)

Ali Ate^,1 inan Keskin,2 Ermedin Toti^,3 and Burak Yefil4

1 Geotechnical Division, Department of Civil Engineering, Duzce University, 81620 Duzce, Turkey

2 Geotechnical Division, Department of Civil Engineering, Karabuk University, 78050Karabuk, Turkey

3 Geotechnical Division, Department of Civil Engineering, Bartin University, 74100 Bartin, Turkey

4 Duzce Technical Science Vocational School Construction Division, Duzce University, 81620 Duzce, Turkey

Correspondence should be addressed to Ali Ates; aliates@duzce.edu.tr Received 7 January 2014; Accepted 19 May 2014; Published 1 July 2014 Academic Editor: Gonzalo Martínez-Barrera

Copyright © 2014 Ali Ates et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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, Vs values 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 (V"s) calculating for a probable earthquake of Mw = 7.2. In the result of the study, the liquefaction potential index (LPI) values were interpreted and compared evaluating the SPT N blow 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 SPT N blow counts were found to be lower than those of the Vs method.

1. Introduction

The liquefaction resistance of soils can be evaluated using laboratory tests such as the cyclic simple shear and cyclic triaxial and cyclic torsional shear tests. Additionally, field methods such as the Standard Penetration Test (SPT), Cone Penetration Test (CPT), and Shear Wave Velocity Test (Vs) can be employed. The occurrence of liquefaction in soils is often evaluated using the simplified procedure originally developed and proposed by Seed and Idriss [1] based on the SPT blow counts correlated with the cyclic stress ratio (CSR), a parameter representing the seismic loading on the soil. This procedure has undergone several revisions and updates [2-4]. In addition to these, procedures have been developed based on the Cone Penetration Test (CPT), Becker Penetration Test (BPT), and small-strain Shear Wave Velocity (Vs) measurements. Youd et al. [2] provided and enhanced

a recent review of the Seed and Idriss simplified procedure and the in situ test methods commonly used to evaluate the liquefaction resistance of soils.

The use of Vs to determine the liquefaction resistance is influenced by factors such as confining stress, plasticity, and relative density [5-7]. In situ Vs can be measured by several seismic tests, including cross hole, down hole, seismic cone penetrometer (SCPT), suspension logger, and spectral analysis of the surface waves (SASW) [8].

During the past two decades, several procedures have been proposed to estimate liquefaction resistance based on Vs [8]. These procedures were developed from laboratory studies [8-15], analytical studies [16, 17], penetration Vs equations [18,19], and in situ Vs measurements at earthquake sites [2022]. Some of these procedures follow the general approach of the Seed-Idriss simplified procedure, in which the Vs is corrected with the cyclic stress ratio. This paper presents

Figure 1: The study area (Duzce Province).

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s= 3> dS \

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0 100 200

Mediterranean □ Study area

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M"d0a"Va Gemiik --_4*ni

Yeni^ehir

Seben B.U. K0LR1 .-.• NATIONAL EARTHQUAKE MONITORING CENTER

Figure 2: View of the Duzce fault [24].

the results of the comparison between the Vs and SPT methods of soil liquefaction potential evaluation carried out in Duzce Province in Turkey. Furthermore, the liquefaction potential indexes (LPI) for both aforementioned methods were calculated using the procedure of Iwasaki et al. [23].

2. Study Area

Duzce Province is located in northwestern Turkey (Figure 1). It is under the effect of the North Anatolian Fault Zone (NAFZ) and is about 30 km distant from the Black Sea. The provincial capital of Duzce is situated on an alluvial soil site.

2.1. Geomorphological and Geological Setting. The study area is situated in an active seismic earthquake zone [24]. Duzce

has been affected by the active faults. The 1957 Bolu (M = 7) and 1967 Adapazari (M = 7.1) earthquakes occurred on the Bolu-Abant Dokurcun segments of the NAFZ. The active and probable active faults of Duzce, Hendek, and C^ilimli are in close proximity to the study area [25] (Figure 2).

During the (M = 7.4) earthquake of 1999, the 30 km eastern segment of the 130 km fault rupture occurred on the western part of the Duzce Fault reaching to Efteni Lake [25]. Duzce plain is an active subsidence and deposition area controlled by lateral strike slip faults surrounded by pre-Quaterney-aged rocks. The oldest is the Yigilca Unit of Eocene-aged caycuma. Formations include volcanic sandstone, rottenstone, andestic and basaltic lavas and volcanic breccia [26]. Quaternary-aged fan, deltaic, and marsh type

Fan (quaternary) Delta (quaternary)

QGd Delta (quaternary)

QGb Marsh (quaternary)

11 I I I I I Surface cracked of 17 August 1999 earthquake

—* Active fault

0 Borehole

■ Trial pit

Marsh (quaternary)

Figure 3: Geological map of the study area and some borehole locations [26].

deposits cover this unit, which consists of gravel, sand, silt, and clay material (Figure 3).

Due to the elevation of the surrounding rocks and as a result of the basin drainage, deposition occurred mostly in the Duzce area and its surroundings (Figure 4). Little Melen (Kucuk Melen) River discharges into the lake and continues flowing towards the only discharge from the lake, the Big Melen (Buyuk Melen) River. In addition, Aksu, Ugursuyu and Aydinpinar Creeks deposit alluvial fans and join in the lake basin. The surrounding rocks are extremely weathered by eroding, allowing the increase in sedimentation. The thickness of the sedimentation is about 260-300 m. The deposition areas have displaced laterally and the horizontal stratigraphy has been altered [25] (Figure 4).

2.2. Seismotectonics of the Study Area. Duzce plain is a pull apart type basin that is controlled by the lateral strike slip fault

Figure 4: View of the deposits in the Duzce area.

system in the NAFZ [28] (Figure 5). Paleo- and neotectonic period active faults exist at the north and south of the plain. There are several faults which are parallel and oblique to these major faults. During the 12 November 1999's earthquake, the surface rupture ranged through Golyaka on the south towards Kaynasli on the east, ending in the Asarsu Valley and

Table 1: Magnitude and damage records of earthquakes around the study area [24].

Locations Date Epicenter Total damage on structures Death Injury

Murefte 09.08.1912 40.60-27.20 7.3 5.540 216 466

Hendek 20.06.1943 40.85-30.51 6.6 No 336 No

Gerede 01.02.1944 41.41-32.69 7.2 20.865 3.959 No

Duzce 10.02.1944 41.00-32.30 5.4 900 No No

Mudurnu 05.04.1944 40.84-31.12 5.6 900 30 No

Yenice 18.03.1953 39.99-27.36 7.4 9.670 265 336

Abant 26.05.1957 40.60-31.20 7.1 4.201 52 100

(¡Cinarcik 18.09.1963 40.77-29.12 6.3 230 1 26

Adapazari 22.07.1967 40.60-30.89 7.2 5.569 89 235

Gelibolu 27.03.1975 40.45-26.12 6.4 980 7 No

Golcuk 13.09.1999 40.80-30.03 5.7 No No Unknown

Duzce 12.11.1999 40.79-31.21 7.2 15.389 845 4.948

Bolu 17.11.1999 40.83-31.51 5.0 No No No

Bolu 22.03.2000 40.94-31.58 5.4 No No No

Yigilca 26.08.2001 40.93-31.53 5.1 No No No

Figure 5: Epicenters of the earthquakes and historical earthquakes in the region [25].

the Bolu Tunnel. The city of Duzce is situated in the middle of the plain on a pressure ridge type hill, probably tectonically controlled. Major earthquake records are given in Table 1. Historical earthquakes have been recorded on the Abant-Bayramoren segment in the south. There were 12 earthquakes between 1967 and 1890. The great earthquake of 17 August, 1668 (Ms = 8), caused a disaster in Anatolia [29], with aftershocks continuing for 6 months [30]. The Bolu-Gerede earthquake (Mm = 7.3) on January 2, 1944, was a major one, recorded after the implementation of instruments for scientific measurement of magnitude. It was noted that 2,381 people died and 50,000 houses were damaged [31]. Although the 17 August, 1999, Marmara and 12 November, 1999, Duzce earthquakes occurred on the western segment of the North Anatolian Fault, the measured average value of the horizontal ground acceleration was 0.54 g in Duzce [32].

obtain undisturbed and disturbed samples and to measure the groundwater level. A Standard Penetration Test (SPT) [33] was carried out during the drillings and SPT N blow counts were obtained in the boreholes. In situ unit weight and moisture content values were obtained from the trial pits. Then, representative soil samples were obtained in order to determine the geomechanical properties of the soils. The 296m-thick alluvium was very heterogeneous and included confined and umconfined aquifers. The groundwater level was mostly at the surface and ranged between 1.5 and 3.9 m.

In this study, the shear wave velocity (Vs) measurements were based on Andrus et al. [27] process for assessing liquefaction potential; Vs values were calculated using empirical equations between shear wave velocity and SPT blow count (N) for all types as follows [34]. The Vs values based on SPT blow count (N) were given below (Table 2):

3. Materials and Methods

3.1. Field Investigations. Geotechnical bore holes were drilled at 40 locations. The depths of the boreholes ranged from 10 to 30 m, which measured to a total of 296 m. These boreholes were utilized to determine the consistency of fine-grained soils and the stiffness of the coarse soils, to

Vs = 61 (1)

= 9 (2)

Vs = 76 • No.33, (3)

Vs = 121 • №■ 27, (4)

Vs = 22 • (5)

Table 2: Field data of Duzce Province.

Boreholes number SPT-N Depth (m) SPT-N WaterLevel Equation (1) (61 • №■ 5) Equation (2) (97 • 314) Shear Wave Velocity Equation (3) (76 • №■ 33) Equation (4) (121 • №-27 ) Equation (5) (22 • №-85 )

BH1 3 32 3.5 345.06 287.99 238.5 308.45 418.7

BH1 9 32 3.5 435.06 287.99 238.5 308.45 418.7

BH2 3 25 3 305 265.5 219.9 288.6 339.4

BH2 6 15 3 236.3 227.02 185.75 251.4 219.9

BH2 15 45 3 409.2 320.5 266.9 338.2 559.3

BH3 4.5 32 4.00 345.06 227.02 185.75 251.4 219.9

BH3 6.00 32 4.00 345.06 227.02 185.75 251.4 219.9

BH3 7.5 28 4.00 322.8 276.17 228.4 297.52 373.7

BH3 12 31 4.00 339.7 285.14 236.02 305.9 407.5

BH4 3.00 31 2.5 339.7 285.14 236.02 305.9 407.5

BH4 6.00 13 2.5 219.95 217.01 177.2 241.9 194.7

BH4 7.5 16 2.5 244 231.7 189.8 255.8 232.3

BH4 9.00 13 2.5 219.94 217.1 177.2 242 194.6

BH4 17.00 13 2.5 219.94 217.1 177.2 242 194.6

BH5 No No No No No No No No

BH6 3.00 28 2.5 322.8 276.2 228.24 297.52 373.7

BH6 4.5 23 2.5 292.54 260 213.9 282.2 316.2

BH6 7.5 21 2.5 279.6 252.3 207.56 275.3 292.7

BH6 12.00 32 2.5 345.06 252.3 207.56 275.3 292.7

BH7 No No No No No No No No

BH8 9.00 11 4.0 202.3 206 167.7 231.2 168.9

BH8 10.50 26 4.0 311.1 269.9 222.7 292 350.9

BH8 13.500 28 4.0 322.8 276.2 228.24 297.52 373.7

BH9 9.00 28 4.00 322.8 276.2 228.24 297.52 373.7

BH9 16.5 81 4.00 549 385.6 324.1 396.4 922

BH10 No No No No No No No No

BH11 7.5 14 3.5 228.3 222.2 182 246.7 207.4

BH11 10.5 40 3.5 386 308.9 256.7 327.6 506.1

BH12 4.5 32 3.25 345.1 252.3 207.56 275.3 292.7

BH12 6.0 36 3.25 366 298.9 248 318.5 463

BH12 10.5 42 3.25 395.4 313.7 260.9 331.9 527.8

BH13 No No No No No No No No

BH14 3.0 15 3.5 236.3 227.02 185.8 251.4 219.9

BH14 4.5 37 3.5 372 302 250.1 320.8 473.6

BH14 6 26 3.5 132.6 269.9 222.8 291.7 350.9

BH14 7.5 30 3.5 334.5 282.3 233.5 303.2 396.7

BH15 No No No No No No No No

BH16 4.5 22 2.5 286.2 256.1 210.8 278.8 304.5

BH17 3.0 13 3.5 219.94 217.1 177.2 242 194.6

BH17 4.5 10 3.5 192.9 199.9 162.5 225.4 155.8

BH17 6.0 21 3.5 279.6 252.3 207.56 275.3 292.7

BH17 7.0 26 3.5 311.1 269.9 222.7 292 350.9

BH18 15 34 4.5 355.7 293.6 243.4 313.6 440.1

BH19 3.0 13 3 219.94 217.1 177.2 242 194.6

BH19 4.5 18 3 258.9 240.1 197.3 264.1 256.7

Table 2: Continued.

Shear Wave Velocity

Boreholes number SPT-N Depth (m) SPT-N WaterLevel Equation (1) (61 • №■ 5) Equation (2) (97 • 314) Equation (3) (76 • №■ 33) Equation (4) (121 • №-27) Equation (5) (22 • №-85)

BH19 7.5 25 3 305 266.6 219.9 288.6 339.4

BH19 13.5 27 3 317 273 255.6 294.9 362.4

BH20 No No No No No No No No

BH21 No No No No No No No No

BH22 No No No No No No No No

BH23 4.5 29 2.0 328.5 279.3 230.8 300.35 385.1

BH23 9.0 8 2.0 172.6 186.4 8.96 212.2 128.9

BH23 10.5 10 2.0 192.9 199.9 162.5 225.4 155.8

BH23 13.5 9 2.0 183 194 157 219 142.5

BH23 15.0 12 2.0 211.4 211.7 172.6 236.7 181.9

BH24 7.5 14 3.5 228.3 222.2 182 246.7 207.4

BH24 10.5 40 3.5 385.8 308.9 256.8 327.6 506.1

BH25 3.0 44 4.5 404.7 318.3 264.9 336.2 548.8

BH25 4.5 14 4.5 228.3 222.2 182 246.7 207.4

BH25 7.5 9 4.5 183 194 157 219 142.5

BH25 10.5 19 4.5 265.9 244.6 200.9 267.9 268.9

BH25 12.0 22 4.5 286.2 256.1 210.8 278.8 304.5

BH26 6.0 13 2.0 219.94 217.1 177.2 242 194.6

BH26 9.0 32 2.0 345.1 252.3 207.56 275.3 292.7

BH27 NO No No No No No No No

BH28 No No No No No No No No

BH29 7.5 27 3.5 317 273 255.6 294.9 362.4

BH29 10.5 23 3.5 292.54 260 213.9 282.2 316.2

BH29 12.0 50 3.5 431.2 331.2 276.4 347.95 612

BH30 No No No No No No No No

BH31 No No No No No No No No

BH32 4.5 7.0 3.0 161.3 178.8 144.5 204.7 115.1

BH32 6.0 32 3.0 345.1 252.3 207.56 275.3 292.7

BH32 9.0 40 3.0 385.8 308.9 256.8 327.6 506.1

BH32 12 54 3.0 448.3 339.5 283.5 355.3 653.1

BH33 No No No No No No No No

BH34 3.0 20 3.0 272.9 248.5 204.3 271.7 280.74

BH34 4.5 21 3.0 279.6 252.3 207.56 275.3 292.7

BH35 3.0 9 2.5 183 194 157 219 142.5

BH35 4.5 8 2.5 172.6 186.4 150.9 212.2 128.9

BH35 7.5 10 2.5 192.9 199.9 162.5 225.4 155.8

BH35 12 12 2.5 211.4 211.7 172.6 236.7 181.9

BH36 3 16 3.5 244 232 189.8 255.8 232.3

BH36 4.5 16 3.5 244 232 189.8 255.8 232.3

BH37 No No No No No No No No

BH38 No No No No No No No No

BH39 No No No No No No No No

BH40 3 20 2.25 272.9 248.5 204.3 271.7 280.74

BH40 4.5 49 2.25 427 329.3 274.5 346.1 602

BH40 9 16 2.25 244 232 189.8 255.8 232.3

Black Sea

(ilimli Fayi^'"

Hendek Fault — - D-Üzce ,, ,

^ Juzce Fault

Figure 6: Identification of seismic sources within 100 km radius of the study area.

3.2. Calculation of Seismic Hazard Design Parameters. The Duzce Fault Zone is situated 13 km south of the study area, the North Anatolian Fault Zone is located 73 km south of the study area, and the Hendek Fault is found 29 km north-west of the study field (Figure 6). The fault zone with the highest possible acceleration in the study site is the North Anatolian Fault Zone. A circle with a radius of 100 km was drawn around the study area in order to identify the seismic design parameters. Within this circle, active seismic sources thought to affect the study field were vertically connected to calculate the shortest routes to the study field in km (Figure 6). These investigations and measurements showed that there were three main fault zones inside the circle. Then, the horizontal flying distances to the study field were calculated as 13 km for the Duzce Fault, 29 km for the Hendek Fault, and 73 km for the North Anatolian Fault [35].

The map of Turkey's active faults published by the Mineral Research and Exploration Institute indicates the total length of the Duzce, Hendek, and North Anatolian Faults as 85 km, 60 km, and 200 km, respectively [35]. The DuzceFault, which is the shortest distance to the study area and has the potential to produce an earthquake, was taken into consideration in the main objective of the study when estimating the next earthquake expected to occur.

According to Mark [39], it is assumed that 1/3 of this fault zone could be ruptured. Therefore, the moment size of the probable seismic design was calculated by using the equation of Wells and Coppersmith [40], as seen below (6):

M = 4.86 + 1.32LogL,

where M is moment magnitude and L is fault length (km).

According to this approach, moment magnitude was calculated to be 7.2 in the case of a rupture of 1/3 of the fault length.

Horizontal earthquake acceleration (peak ground acceleration, PGA) was calculated by using the attenuation

relationship (7) developed for faults based on the earthquakes in Turkey [41]:

PGA - 2 1gg0'0218(33'3M^-Re +7.8427Sa+18.9282Sb) (7)

where SA - 0 and SB - 1 values are used for soft soils, Re is the shortest horizontal flying length to the respective fault zone from the settlement, and is the magnitude of the earthquake. The peak horizontal earthquake acceleration that can be created by the seismic design was found to be 0.28 g.

4. Assessment of Liquefaction Potential

Prediction of the liquefaction potential of soils is based on cyclic laboratory testing on soil samples and use of in-situ tests and empirical methods. However, the use of laboratory testing is complicated due to difficulties associated with sample disturbance during both sampling and reconsolidation. Thus, empirical approaches based on the in-situ penetration test results have gained popularity in engineering practice as well as in engineering codes [42].

In this study, after obtaining the in situ test results, the evaluation of the liquefaction procedure was begun. The evaluation procedures based on the Standard Penetration Test (SPT) [43] and measurement of shear wave velocity (Vs) [27] require the measurement of three parameters: (1) the level of cyclic loading on the soil caused by the earthquake, expressed as an acyclic stress ratio (CSR); (2) the stiffness of the soil, expressed as over burden stress (corrected SPT blow count) due to shear wave velocity; and (3) the resistance of the soil to liquefaction, expressed as a cyclic resistance ratio (CRR). Guidelines for calculating each parameter are presented below [44].

4.1. Cyclic Stress Ratio (CSR). The cyclic stress ratio (CSR) characterizes the seismic demand induced by a given earthquake, and it can be determined from peak ground surface acceleration that depends upon site-specific ground motions [45]. The expression for the CSR induced by earthquake ground motions formulated by Idriss and Boulanger [46] is as follows:

CSR = 0.65-

ov _1__

a^ fd MSF KCT'

where 0.65 is a weighing factor to calculate the equivalent uniform stress cycles required to generate the same pore water pressure during an earthquake; the amax is the peak horizontal ground acceleration; g is the acceleration of gravity; <jy and a^ are total vertical overburden stress and effective vertical overburden stress, respectively, at a given depth below the ground surface; rd is the depth-dependent stress reduction factor; MSF is the magnitude scaling factor; and K<r is the overburden correction factor.

The stress reduction factor (rd) accounts for the dynamic response of the soil column and represents the variation of shear stress amplitude with depth. Idriss and Boulanger [46]

formulated the following expressions to calculate the stress reduction factor (rd) (9)-(11):

rd = exp [a(z) + ^(z)Mj ,

a(z) = -1.012 - 1.126sin(—^ + 5.133), v y V 11.73 )

ß(z) = 0.106 + 0.118 sin

+ 5.142

where z is the depth (m) and is the moment magnitude. The arguments inside the sine terms in (10) and (11) are in radians. The above expression for rd is valid up to a depth of z < 34 m, and the depths of the boreholes considered in the present analysis were less than 34 m.

The values of CSR that pertain to the equivalent uniform shear stress induced by an earthquake of magnitude, = 7.5, were adjusted to an equivalent CSR for an earthquake of magnitude = 7.5 through the introduction of the magnitude scaling factor (MSF), which accounts for the duration effect of ground motions. The MSF for < 7.5 is expressed as follows (12):

MSF = 6.9 exp ) - 0.058 < 1.8.

Since the liquefaction resistance increases with increasing confining stress, the overburden correction factor (Ka) was applied such that the values of CSR were adjusted to an equivalent overburden pressure a^ of 1 atmosphere equations (13)-(14):

KCT = 1 - Ca

< 1.0,

18.9 - 2.5507^(N1)6 Pa is the atmospheric pressure (= 00 kPa).

4.2. Corrected SPT Blowcount and Shear Wave Velocity. In this study, the measured SPT N values (N) were corrected for overburden stress, energy ratio, diameter of boreholes, length of sampling rod, and the type of sampler by introducing a series of correction factors. N"60 is the corrected N"m value for a 60% energy ratio with an assumption that 60% of the energy was transferred from the falling hammer to the SPT sampler. The corrected (^)60 values were calculated as follows (15):

(Ni)60 - N"mCNCECBCfiCfi,

where CN is a factor to normalize N"m to a common reference effective overburden stress; CE is the correction for the hammer energy ratio (£B); CB is the correction factor for borehole diameter; CB is the correction factor for rod length; and Cs is the correction for samplers with or without liners. The value of CN was calculated as per (15) and was limited to a maximum value of 1.7. Cs, CB, and CE were assumed to be 1.1,

Table 3: The rod length correction with respect to the depth.

Depth Correction for rod length

(9) d cR

d < 3 m 0.75

(10) d = 3-4 m 0.8

d = 4-6 m 0.85

(11) d = 6-10 m 0.95

d = 10-30 m 1.0 m

1.0, and 0.6, respectively. Rod length correction with respect to the depth (CB) at each borehole location was corrected as shown in Table 3, as suggested by Youd and Idriss [47].

The overburden correction (CN) factor to normalize )eo to a common reference effective overburden stress is as follows (16)-(17):

< 1.7,

a - 0.784 - 0.0768^(N1)6

It can be observed from (16) and (17) that (^)60 and CN are interdependent. A series of iterations were carried out to determine (N:)60 and CN until the difference between successive iteration values was less than 0.001.

In addition, shear wave velocities had to be corrected. In the procedure of liquefaction potential evaluation proposed by Andrus et al. [27], shear wave velocity was corrected to overburden stress and (18) was suggested:

Vsi =VSi ( £

where Vs is the shear wave velocity (m/s); VS1 is the stress-corrected shear wave velocity (m/s); Pa is the atmosphere pressure equal to 100 kPa; a^ shows the the effective overburden stress; and K^ is the coefficient of effective earth pressure (in this study assumed equal to 0.5) [44].

4.3. Evaluation of the Cyclic Resistance Ratio (CRR). Determination of the cyclic resistance ratio (CRR) requires fines content (FC) of the soil to correct updated SPT blow count (N1 )60 to an equivalent clean sand standard penetration resistance value (N1 )60cs. Idriss and Boulanger [46] determined the CRR value for cohesionless soil with any fines content using the following expression (19)-(21):

CRR - exp

V 25.4

2.8 " T

y^iLcs

(NiWs = (^i)60 + A(Ni)6

3 G 0.2

Field performance

Fines content

Liq. No liq.

>35 20 <5 Fines content (%)

Data based on

Mw = 5.9 to 8.3; adjusted by dividing CSR by (Mw/7.5) 2.56 Uncemented, Holocene-age soil Average values of Vsl and Omgx

No liquefaction

0 100 200

Stress-corrected shear wave velocity V (m/s)

Figure 7: Recommended curves for evaluating CRR from shear wave velocity Vs for clean, uncemented soils with liquefaction data from compiled case histories [27].

where A(N1)60 is the correction for fines content in percent (FC) present in the soil and is expressed as

A(N,)„ = exp (L«+ jC^FC+y1)

Separately, as regarding the use of Vs as an index of liquefaction resistance, it has been illustrated by several authors. The most popular CRR-Vj correlation (Figure 7) was proposed by Andrus and Stokoe [22] for uncemented Holocene-age soils, based on a database including 26 earthquakes and more than 70 test sites. The CRR is obtained as a function of an overburden-stress corrected shear wave velocity VS1 = Vs(Pa/^Y0) ' , where Vs = measured shear wave velocity, Pa = atmospheric pressure (= 100 kpa), and o^0 = initial effective vertical stress (same units as Pa). Andrus et al. [27] introduced age correction factors to extend the original correlation of Andrus and Stokoe [22] to soils older than Holocene. Their CRR-VS1 relationship (curves in Figure 7, for various fines contents) is approximated by:

KalVSi 100

Vs*i -KaiVsl Vs*

where Vs* = the limiting upper value of VS1 for liquefaction occurrence (Vs* = 200 m/s for the curve for fines content >35%); Vs* = 215 m/s for the curve for fines content <5%; Vs* varies linearly from 200 to 215 m/s for fines content between 35 and 5%; Ka1 = factor to correct for high VS1 values caused by aging; and Ka2 = Factor to correct for influence of age on CRR. Magnitude scaling factors should be used to scale (22) (for magnitude Mw = 7.5 earthquakes) to different magnitudes. Both Ka1 and Ka2 are 1 for uncemented soils of Holocene age. For older soils, suggested Ka1 values (mostly in

Table 4: The level of liquefaction severity.

LPI Iwasaki et al. Luna and Frost MERM

[23] [37] [38]

LPI = 0 Very low Little to none None

0 < LPI < 5 Low Minor Low

5 < LPI < 15 High Moderate Medium

15 < LPI Very high Major High

the range 0.6 to 0.8) are derived from SPT-VS1 relationships (e.g. Ohta and Goto [48], Rollins et al. [49], or site specific). Lower-bound values of Ka2 (1.1 to 1.5) are based on the study by Arango et al. [50]. However, Andrus et al. [27] noted the associated high uncertainty and the need for additional work to quantify the influence of age on CRR, as well as on Vs.

4.3.1. Determination of the Factor of Safety. The factor of safety against liquefaction (FS) is commonly used to quantify liquefaction potential. The factor of safety against liquefaction (FS) can be defined as follows:

(CRR),

Mm=T.5,a<

Both CSR and CRR vary with depth and, therefore, the liquefaction potential is evaluated at corresponding depths within the soil profile.

4.3.2. Determination of the Liquefaction Potential Index. The liquefaction potential index (LPI) is a single-valued parameter to evaluate regional liquefaction potential. The LPI at a site is computed by integrating the factors of safety (FS) along the soil column up to a depth of 20 m. A weighting function is added to give more weight to the layers closer to the ground surface. The liquefaction potential index (LPI) proposed by Iwasaki et al. [36, 51] is expressed as follows (24). The criteria of the level of liquefaction severity indexes were given below (Table 4):

where z is the depth of the midpoint of the soil layer (0 to 20 m) and dz is the differential increment of depth. The weighting factor, W(z), and the severity factor, F(z), are calculated as per the following expressions (25):

F(z)=1- FS for FS <1.0, F (z) = 0 for FS > 1.0, W(z)=10-0.5z for z < 20 m, W(z) = 0 for z > 20 m.

For the soil profiles with depths of less than 20 m. The LPI was calculated using the following expression [37] (26)-(27):

LPI = X^F.H,

0.00 -T 1.00 -2.00 -3.00 -4.00 -5.00 -6.00 -7.00 -8.00 -9.00 -10.00 11.00 12.00 13.00 14.00 -15.00

Vs data graph

Fines content

Shear stress ratio

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 -15.00

100 200 300

Vs (m/s)

- FC (%)

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00

CSR CRR

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00

Factor of safety

0 1 2 3 4 5

F.S. = 1

Figure 8: Borehole 23 was chosen to check and compare for liquefaction potential as a sample according to shear wave velocity values.

F; = 1 - FS; for FS; < 1.0,

Fj = 0 for FS; > 1.0,

where H; is the thickness of the discretized soil layers; n is the number of layers; Ft is liquefaction severity for (th layer; FS; is the factor of safety for (th layer; Wt is the the weighting factor (= 10 - 0.5Z;); and Zi is the depth of (th layer (m).

5. Assessment of the Liquefaction Potential Index

The city of Duzce has been reconstructed since the 12 November earthquake of 1999. The general form of construction had typically been a 4-5-storey reinforced-concrete frame and masonry structure. After the 12 November Duzce earthquake experience, regulations were changed to limit construction to 2-3-storey buildings. The city is located over deep alluvial deposits. The main soils deposited at this site are comprised of alluvial sand and silt. The boreholes in Duzce were drilled around the Efteni Lake at a depth of 200 m and did not reach bedrock. The shallow soils at approximately 10 m are recent deposits laid down by the Aksu and Melen Rivers that flooded the area.

Turkey is located in the active tectonic region of the Alp Himalayan Earthquake Zone, so this area is an active region seismologically. There are several active tectonic sections in Turkey, such as the North Anatolian Fault Zone, the East Anatolian Fault Zone, the West Anatolian Grabens, the Ecemis Fault Zone, and the Tuzgolu Fault Zone [52]. Duzce Province is located near the Duzce Fault segment of the North Anatolian Fault Zone which is active in the Western Black Sea

V (m/s)

Figure 9: Borehole 23 was chosen to check and compare for liquefaction potential as a sample for shear wave velocity.

Region. Furthermore, this area consists of granular alluvial deposits which are loose to the surface. The groundwater is between 2.5 and 4 m below the surface and changes seasonally. For the analysis of the liquefaction potential index of Duzce Province, a total of 40 geotechnical boreholes were drilled by the General Directorate of Mineral Research and Exploration. The field data of the works were assessed for the liquefaction potential index for Duzce Province. The SPT samples were implemented at depth intervals of 1.5 m from the first to the last of the boreholes, and the disturbed samples were used to describe the grain size distribution and Atterberg limits of the soils. The boundaries of the soil layers, SPT-N values, fines content, and the liquid limit for all layers

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00

SPT data graph

Shear stress ratio

0.00 0.50 1.00 1.50 2.00

2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 -15.00

I i i i

0 10 20 30 40 50

- Field SPT

-X- (Ni)(60)

* (N1 )(60)cs

0.00 0.50 -4 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00

Factor of safety

0 0.5 1 1.5 2

CSR CRR

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00

Settlements (cm)

0 1 2 3 4 5

F.S. = 1

9.85 19.85 29.85

- Total l Point

Figure 10: Borehole 23 was chosen to check and compare for liquefaction potential as a sample according to the SPT-N values.

M, = 71/2, a = 1 atm base curve

0.6 0.5 0.4 0.3 0.2 0.1 0

0 5 10 15 20 25 30 35 40

(Nl)(60)cs

Figure 11: Borehole 23 was chosen to check and compare for liquefaction potential as scattering liquefaction points of sample for SPT-N values.

Lique action

42 35 4 ■■ 1 A

No liquefi ction

throughout the boreholes were employed as input parameters to determine the liquefaction potential index.

In addition, the magnitude of the earthquake and the maximum horizontal acceleration of those parameters to be created due to local faults were used here for evaluating the liquefaction potential index. The Duzce Fault Zone of the North Anatolian Fault Zone and surrounding zones were generated and showed an average of 7.2 moment magnitudes. For this reason, the magnitude of the projected earthquake was found by using 7.2 for the calculations. In this context, the typical computation of factors of safety against liquefaction for earthquakes (Mw = 7.2) yielded by the Duzce Fault Zone was carried out at the chosen borehole using (2) through (20). The LPI at this particular site was calculated from the FS

values based on the expression by Luna and Frost [37]. The LPI values were computed at the study site for magnitudes of Mw = 7.2.

Great effort was taken in the analysis of the other input parameter for determining the liquefaction potential, the maximum ground acceleration (amax). However, some researchers have offered empirical equations for the maximum ground acceleration [41, 53, 54]. In particular, the comprehensive study of Ulusay et al. [41] should be mentioned as it relates to the iso-acceleration map of Turkey. In this study, the amax values were calculated as approximately 502 gal for the Duzce Fault Zone segment. The liquefaction potential index indices for 40 boreholes were calculated and are given in Table 5 and Figures 8, 9,10, and 11. In addition,

Table 5: Liquefaction potential index results.

Boreholes number Equation (1) The level of liquefaction severity (LPI) Equation (2) Equation (3) Equation (4) Equation (5)

BH1 0 0 0 0 0

BH2 0 0 14.14 19.79 0

BH3 0 0 35.63 0 0

BH4 30.32 13.35 39.17 0 28.97

BH5 Not performed 0 Not performed Not performed Not performed

BH6 0 0 23.09 0 0

BH7 Not performed Not performed Not performed Not performed Not performed

BH8 46.83 33.46 26.34 5.82 40.87

BH9 0 0 0 0 0

BH10 Not performed Not performed Not performed Not performed Not performed

BH11 5.43 0 0.8 0 24.39

BH12 0 0 0 0 0

BH13 Not performed Not performed Not performed Not performed Not performed

BH14 0 9.14 0 0 0

BH15 Not performed Not performed Not performed Not performed Not performed

BH16 0 0 0 0 0

BH17 10.5 5.37 0 0 8.90

BH18 0 0 0 0 0

BH19 0 0 24.17 0 0

BH20 Not performed Not performed Not performed Not performed Not performed

BH21 Not performed Not performed Not performed Not performed Not performed

BH22 Not performed Not performed Not performed Not performed Not performed

BH23 23.86 36.96 35.26 42.53 40.84

BH24 1.5 0 19.89 35.34 26.39

BH25 17.85 14.52 14.68 8.48 19.94

BH26 5.68 0 41.81 0 22.44

BH27 Not performed Not performed Not performed Not performed Not performed

BH28 Not performed Not performed Not performed Not performed Not performed

BH29 0 8 9.51 0 0

BH30 Not performed Not performed Not performed Not performed Not performed

BH31 Not performed Not performed Not performed Not performed Not performed

BH32 33.05 22.94 32.74 0 30.74

BH33 Not performed Not performed Not performed Not performed Not performed

BH34 0 0 0 0 0

BH35 66.53 31.64 56.95 2.84 59.78

BH36 0 0 9.67 0 0

BH37 Not performed Not performed Not performed Not performed Not performed

BH38 Not performed Not performed Not performed Not performed Not performed

BH39 Not performed Not performed Not performed Not performed Not performed

BH40 0 0 18.88 0 0

Liquefaction potential index percent Liquefaction potential indra ^rcert Liquefaction potential index percent distribution according to equation (1) distribution according to equation (2) distribution according to equation (3)

v4.10%

^.10% 4.10o/o\

(a) (b) (c)

Liquefaction potential index percent Liquefaction potential index percent distribution according to equation (4) distribution according to equation (5)

Low ■ Very high High

Figure 12: Pie charts showing the areas of the potential zones.

the distributions of liquefaction potential indexes are presented in Figure 12 as a pie chart.

6. Results and Conclusions

The evaluation of the liquefaction potential of a liquefaction-prone area is of vital importance in geotechnical earthquake engineering, both for assessment for site selection and for planning and construction. This study investigated two field methods used to evaluate the liquefaction potential of soils, the Standard Penetration Test (SPT) and the Shear Wave Velocity Test (Vs), based on the empirical relationships between them. Attempts were made to evaluate the factors of safety against liquefaction (FS) and corresponding liquefaction potential indices (LPI) for a local fault zone in order to produce the seismic movement for the province using SPT-N-based semiempirical procedures.

The concept of the liquefaction potential index was used in this study for liquefaction susceptibility, as proposed by Iwasaki et al. [36]. The distribution of the LPI was generated in order to predict the occurrence of damaging liquefaction for an earthquake to be yielded by the local fault zone in Duzce Province in the Western Black Sea Region of Turkey. This study area is under the effect of the North Anatolian Fault Zone through its segment, the Duzce Fault Zone, which was evaluated for producing the liquefaction potential indices by calculating for a probable earthquake of Mw = 7.2.

The comparison of the safety factors and liquefaction potential indexes reveal that the severity of liquefaction

occurrences in the study area based on the Vs methods (Equation (1) = 43.86, equation (2) = 40.84, equation (3) = 42.53, equation (4) = 36.96, equation (5) = 43.86) are bigger than the one based on the SPT method (35,36). Moreover, it can be observed that the relationships between the SPT method and the shear wave velocity are not suitable. Because the relationships used in the present study are dependent on soil type, fines content, type of tests, and their accuracy, it might be more valid to perform both methods for the same place and then compare the results in order to evaluate the liquefaction potential.

Finally, a very high susceptibility category of liquefaction was observed for the potential earthquake of Mw = 7.2; however, 3.8-10.2% of the study area is in the highly susceptible liquefaction class in five distribution charts according to (1)-(5). The percentage that is moderately susceptible takes up the least area from the other class: 1.2-4.1% for all locations in the distribution charts. The low susceptibility areas are 28.76-65%, respectively.

In conclusion, the areas developed on reclaimed land having large, thick deposits of soft soil and shallow groundwater levels were observed to be more prone to liquefaction. This paper reveals that some of the areas are more highly prone to liquefaction due to the greater thickness of the soft soil deposits and groundwater table at shallow depths. It can be observed from the distribution of the LPI that a high degree of liquefaction would occur at several sites in the Province of Duzce during a seismic event. These LPI distributions will

help the structural designers and city planners to check the vulnerability of the area against liquefaction.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

Acknowledgments

The authors would like to express their gratitude to the Duzce Provincial Governorate and the General Directorate of Mineral Research and Exploration for information and the logs of geotechnical boreholes.

References

[1] H. B. Seed and I. M. Idriss, "Simplified procedure for evaluating soil liquefaction potential," Journal of the Soil Mechanics and Foundations Division, vol. 97, no. 9, pp. 1249-1273,1971.

[2] T. L. Youd, I. M. Idriss, R. D. Andrus et al., "Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation ofliquefaction resistance of soils," Journal ofGeotechnical and Geoenvironmen-tal Engineering, vol. 127, no. 10, pp. 817-833, 2001.

[3] H. B. Seed, I. M. Idris, and I. Arango, "Evaluation ofliquefaction potential using field performance data," Journal of Geotechnical Engineering, vol. 109, no. 3, pp. 458-482,1983.

[4] H. B. Seed, K. Tokimatsu, L. F. Harder, and R. M. Chung, "The influence of SPT procedures in soil liquefaction resistance evaluation," Journal of Geotechnical Engineering, vol. 111, no. 12, pp. 1425-1445,1985.

[5] B. O. Hardin and V. P. Drnevich, "Shear modulus and damping in soils: design equation and curves," Journal ofSoil Mechanics and Foundation, vol. 98, no. 7, pp. 667-692,1972.

[6] S. Kramer, Geotechnical Earthquake Engineering, Prentice Hall, Upper Saddle River, NJ, USA, 1996.

[7] K. Ishihara, Soil Behaviour in Earthquake Geotechnics, Oxford Engineering Science Series, Oxford University Press, Oxford, UK, 1996.

[8] A. F. Rauch, M. Duffy, and K. H. Stokoe II, "Laboratory correlation of liquefaction resistance with shear wave velocity," in Proceedings of the Sessions of Computer Simulation of Earthquake Effects (Geo-Denver '00),vol. 110, pp. 66-80, Denver, Colo, USA, August 2000.

[9] Y.-T. Huang, A.-B. Huang, Y.-C. Kuo, and M.-D. Tsai, "A laboratory study on the undrained strength of a silty sand from Central Western Taiwan," Soil Dynamics and Earthquake Engineering, vol. 24, no. 9-10, pp. 733-743, 2004.

[10] C. Yunmin, K. Han, and C. Ren-Peng, "Correlation of shear wave velocity with liquefaction resistance based on laboratory tests," Soil Dynamics and Earthquake Engineering, vol. 25, no. 6, pp. 461-469, 2005.

[11] Y.-G. Zhou, Y.-M. Chen, and B. Huang, "Experimental study of seismic cyclic loading effects on small strain shear modulus of saturated sands," Journal ofZhejiang University: Science, vol. 6, no. 3, pp. 229-236, 2005.

[12] N. Liu, J. K. Mitchell, and M. Hon, "Influence of nonplastic fines on shear wave velocity-based assessment ofliquefaction," Journal of Geotechnical and Geoenvironmental Engineering, vol. 132, no. 8, pp. 1091-1097, 2006.

[13] Y.-G. Zhou and Y.-M. Chen, "Laboratory investigation on assessing liquefaction resistance of sandy soils by shear wave velocity," Journal of Geotechnical and Geoenvironmental Engineering, vol. 133, no. 8, pp. 959-972, 2007.

[14] C. D. P. Baxter, A. S. Bradshaw, R. A. Green, and J.-H. Wang, "Correlation between cyclic resistance and shear-wave velocity for providence silts," Journal of Geotechnical and Geoenvironmental Engineering, vol. 134, no. 1, pp. 37-46, 2008.

[15] F. Askari, R. Dabiri, A. Shafiee, and M. K. Jafari, "Liquefaction resistance of sand-silt mixtures using laboratory-based shear wave velocity," International Journal of Civil Engineering, vol. 9, no. 2, pp. 135-144, 2011.

[16] R. D. Andrus, In-situ characterization of gravelly soils that liquefied in the 1983 Borah Peak earthquake [Ph.D. thesis], University Of Texas, Austin, Tex, USA, 1994.

[17] R. Dabiri, F. Askari, A. Shafiee, and M. K. Jafari, "Shear wave velocity-based liquefaction resistance of sand-silt mixtures: deterministic versus probabilistic approach," Iranian Journal of Science and Technology—Transaction of Civil Engineering, vol. 35, no. 2, pp. 199-215, 2011.

[18] A. L. Lodge, Shear wave velocity measurements for subsurface characterization [Ph.D. thesis], University of California, Berkeley, Calif, USA, 1996.

[19] K. Kayabali, "Soil liquefaction evaluation using shear wave velocity," Engineering Geology, vol. 44, no. 1-4, pp. 121-127,1996.

[20] R. D. Andrus and K. H. Stokoe, "Liquefaction resistance based on shear wave velocity," in Proceedings of the NCEER Workshop on Evaluation of Liquefaction Resistance of Soils, T. L. Youd and I. M. Idriss, Eds., Technical Report NCEER-97-0022, pp. 89-128, National Center for Earthquake Engineering Research, Buffalo, NY, USA, Salt lake City, Utah, USA, January 1997 1996.

[21] C. H. Juang, C. J. Chen, W. H. Tang, and D. V. Rosowsky, "CPT-based liquefaction analysis, part 1: determination of limit state function," Geotechnique, vol. 50, no. 5, pp. 583-592, 2000.

[22] R. D. Andrus and K. H. Stokoe II, "Liquefaction resistance of soils from shear-wave velocity," Journal of Geotechnical and Geoenvironmental Engineering, vol. 126, no. 11, pp. 1015-1025, 2000.

[23] T. Iwasaki, K. Tokida, F. Tatsuoka, S. Watanabe, S. Yasuda, and H. Sato, "Microzonation for soil liquefaction potential using simplified methods," in Proceedings of the 3rd International Conference on Microzonation, pp. 1319-1330, Seattle, Wash, USA, June-July 1982.

[24] NEMC, B.U. Kandilli Observatory and Earthquake Research Institute, National Earthquake Monitoring Centre, 2014, http:// www.koeri.boun.edu.tr/sismo.

[25] Tubitak-AU-MTA, Investigation of Alternative Settlement Area after 17 August 1999 Earthquake in Duzce District (Bolu), Ankara, Turkey, 1999.

[26] O. Emre, T. Y. Duman, and A. Dogan, The Preassessment Report and Map of Surface Rapture in 17 August 1999 Eastern Marmara Earthquake, No. 22, General Directorate of Mineral Research and Exploration, Ankara, Turkey, 1999.

[27] R. D. Andrus, P. Piratheepan, B. S. Ellis, J. Zhang, and C. H. Juang, "Comparing liquefaction evaluation methods using penetration Vs relationships," Soil Dynamics and Earthquake Engineering, vol. 24, no. 9-10, pp. 713-721, 2004.

[28] E. Gokten, V. Ozaksoy, and R. Demirtas, "Some neotectonical properties ofthe North Anatolian fault zone between bayramo-ren-abant (Turkey)," in Active Tectonic Research Group First Meeting Proceeding, pp. 68-77, ITU Mining Faculty-Eurasia Earth Sciences Institute, 1998.

[29] R. Demirtas, Kuzey anadolufay zonunun abant-gerede arasinda kalan bolumunun neotektonik Ozellikleri ve paleosis-misitesi [Ph.D. thesis], University of Ankara, Ankara, Turkey, 2000.

[30] N. N. Ambraseys, "Engineering seismology," Earthquake Engineering & Structural Dynamics, vol. 17, no. 1, pp. 1-105,1988.

[31] C. Tasman, "The Report About The Gerede-Bolu Earthquake," DAD/At. 46,1944 (Turkish).

[32] T. Ugras, Z. Colakoglu, U. Ceken et al., "17 Agustos.Izmit Korfezi Depremi Kuvvetli Yer Hareketi Kayitlarinin Degerlen-dirilmesi," 17 Agustos.Izmit Korfezi Deprem Raporu, Bayin-dirlik Ve Iskan Bakanligi, Afet Isleri Genel Mudurlugu, Deprem Arastirma Dairesi, Ankara, Pp 156-189, 2000, (Turkish).

[33] American Society for Testingmaterials, "Standard test for penetration test and split-barrel sampling of soils (ASTM D1596)," in Annual Book of ASTM Standards, vol. 04. 09, Section 4, p. 1092, 1994.

[34] M. K. Jafari, A. Shafiee, and A. Razmkhah, "Dynamic properties of fine grained soils in south of tehran," Journal of Seismology and Earthquake Engineering, vol. 4, no. 1, pp. 25-36, 2002.

[35] F. Saroglu, O. Emre, and I. Kus^u, Turkiye Diri Fay Haritasi, MTA Genel Mudurlugu, Ankara, Turkey, 1992.

[36] T. Iwasaki, K. Tokida, F. Tatsuko, and S. Yasuda, "A practical method for assessing soil liquefaction potential based on case studies at various sites in Japan," in Proceedings of the 2nd International Conference on Microzonation, pp. 885-896, San Francisco, Calif, USA, November-December 1978.

[37] R. Luna and J. D. Frost, "Spatial liquefaction analysis system," Journal of Computing in Civil Engineering, vol. 12, no. 1, pp. 4856, 1998.

[38] Microzonation for Earthquake Risk Mitigation (MERM), Microzonation Manual, World Institute for Disaster Risk Management, 2003.

[39] R. K. Mark, "Application of linear statistical model of earthquake magnitude versus fault length in estimating maximum expectable earthquakes," Geology, vol. 5, no. 8, pp. 464-466, 1977.

[40] D. L. Wells and K. J. Coppersmith, "New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement," Bulletin of the Seismological Society ofAmerica, vol. 84, no. 4, pp. 974-1002, 1994.

[41] R. Ulusay, E. Tuncay, H. Sonmez, and C. Gokceoglu, "An attenuation relationship based on Turkish strong motion data and iso-acceleration map of Turkey," Engineering Geology, vol. 74, no. 3-4, pp. 265-291, 2004.

[42] A. Ansal and G. Tonuk, "Source and site effects for microzonation," in Earthquake Geotechnical Engineering: 4th International Conference on Earthquake Geotechnical Engineering-Invited Lectures, K. Pitilakis, Ed., Geotechnical Geological and Earthquake Engineering, Chapter 4, pp. 73-92, Geotechnical Geological and Earthquake Engineering, 2007.

[43] H. B. Seed, K. Tokimatsu, L. F. Harder, and R. M. Chung, "The influence of SPT procedures in soil liquefaction resistance evaluations," Journal of Geotechnical Engineering, vol. 111, no. 12, pp. 1425-1445,1985.

[44] M. K. Noutash, R. Dabiri, and M. H. Bonab, "The evaluation of soil liquefaction potential using shear wave velocity based on empirical relationships," International Journal of Engineering, vol. 6, no. 4, 2012.

[45] J. Dixit, D. M. Dewaikar, and R. S. Jangid, "Assessment of liquefaction potential index for Mumbai city," Natural Hazards and Earth System Science, vol. 12, no. 9, pp. 2759-2768, 2012.

[46] I. M. Idriss and R. W. Boulanger, "Semi-empirical procedures for evaluating liquefaction potential during earthquakes," Soil Dynamics and Earthquake Engineering, vol. 26, no. 2-4, pp. 115130, 2006.

[47] T. L. Youd and I. M. Idriss, "Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils," Journal of Geotechnical and Geoenvironmental Engineering, vol. 127, no. 4, pp. 297-313, 2001.

[48] Y. Ohta and N. Goto, "Empirical shear wave velocity equations in terms of characteristic soil indexes," Earthquake Engineering and Structural Dynamics, vol. 6, no. 2, pp. 167-187,1978.

[49] K. M. Rollins, N. B. Diehl, and T. J. Weaver, "Implications of VS-BPT (N1)60 correlations for liquefaction assessment in gravels," in Geotechnical Earthquake Engineering and Soil Dynamics III, vol. 1 of Geotechnical Special Publication No. 75, pp. 506-517, ASCE, 1998.

[50] I. Arango, M. R. Lewis, and C. Kramer, "Updated liquefaction potential analysis eliminates foundation retrofitting of two critical structures," Soil Dynamics and Earthquake Engineering, vol. 20, no. 1-4, pp. 17-25, 2000.

[51] T. Iwasaki, K. Tokida, F. Tatsuoka, S. Watanabe, S. Yasuda, and H. Sato, "Microzonation for soil liquefaction potential using simplified methods," in Proceedings of the 2nd International Conference on Microzonation, pp. 1319-1330, Seattle, Wash, USA, 1982.

[52] A. Yalcin, C. Gokceoglu, and H. Sonmez, "Liquefaction severity map for Aksaray city center (Central Anatolia, Turkey)," Natural Hazards and Earth System Science, vol. 8, no. 4, pp. 641-649, 2008.

[53] W. B. Joyner and D. M. Boore, "Peak horizontal acceleration and velocity from strong-motion records from the 1997 imperial valley, California earthquake," Bulletin of the Seismological Society of America, vol. 71, no. 6, pp. 2011-2038,1981.

[54] O. Aydan, M. Sezai, and T. Yarar, "The seismic characteristics of Turkish earthquakes," in Proceedings of the 11th International Conference on Earthquake Engineering, pp. 1-8, Acapulco, Mexico, 1986.

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