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The open or in-filled trenches are often used in engineering practice to mitigate ground vibration induced by different types of vibration sources. A novel approach which is considering the effect of Rayleigh wavelength on the efficiency of open and in-filled trenches coupled with regular specific normalized dimensions was implemented in this study. While impact loading is a very common type of loading (in, e.g., machine foundations, driven pile installation), it was rarely studied in the past. The loading is selected to consist of 12 impact pulses. In this study, it was shown that Rayleigh wavelength controls the effect of trench-normalized dimensions on its performance, and therefore, studying the trench effectiveness based only on its normalized dimensions is a limited assumption. For open trenches, the depth of trench is the key parameter controlling its efficiency, while its width does not have a significant effect except for shallow trenches (normalized width of less than 0.7) in the condition of low Rayleigh wavelength (2.0 m). Also, it was shown that the trench should be installed at a normalized distance of at least 1.0. Furthermore, the numerical results revealed that the effect of the normalized width of the geofoam trench on its efficiency for Rayleigh wavelength $${\lambda }_{R}=2.0 \, \mathrm{m}$$ λ R = 2.0 m was more than that for $${\lambda }_{R}=8.0 \, \mathrm{m}$$ λ R = 8.0 m . Also, several graphs for the design of geofoam trenches under different Rayleigh wavelengths were proposed in this study, which could be useful in practice.

Drilled shafts are one of the most important types of pile foundations Several researchers have suggested different soil failure patterns for driven piles however for drilled shafts this issue is inadequately addressed in the literature In this paper a numerical approach was pursued to obtain the location and dimensions of plastic zones around the tip of drilled shafts The dependence of the suggested failure pattern size on the soil properties and drilled shaft dimensions was investigated Based on several analyses a soil jug shaped failure pattern around the tip of drilled shafts was proposed and its dimensions were determined using the regression based and trial and error analyses A c Comparison of is made between the proposed failure pattern obtained in this study for drilled shafts with the ones reported in the literature that were based on the logarithmic spiral curve and also cavity expansion theory showed that This study shows that the suggested failure pattern hasd some similarities with the one proposed based on the cavity expansion theory Finally based on the suggested plastic zone an analytical approach was used introduced to estimate the tip resistance for drilled shafts in sand Good agreement between the analytically predicted results and measured values of tip resistance reported in the literature was found 2021 Informa UK Limited trading as Taylor Francis Group

Do all the clayey soils have the same behavior in terms of the generation and dissipation of excess pore water pressure during the piezocone penetration process? To find the answer, a coupled numerical simulation of CPTu in clays based on finite element analysis is presented in this paper. In this regard, the numerical modeling is verified by some laboratory tests on the samples with known initial conditions and stress states as well as field measurements of piezocone testing. Generation of excess pore water pressure during the penetration process is then investigated at different locations around the cone. This study encompasses piezocone penetration in both normally consolidated and heavily overconsolidated clayey soils. The dissipation of induced excess pore water pressures is also examined by stopping the cone after penetrating into the soil. The obtained results show that the measured excess pore water pressure at the cone shoulder is a key parameter for interpreting the soil behavior in terms of the generation and dissipation of excess pore water pressure around the piezocone during the penetration process. Caution should, therefore, be exercised to use existing correlations for estimating the flow characteristic parameters of cohesive soils (e.g. the coefficients of permeability and consolidation) from the piezocone test results.

We performed an experimental study to investigate the effects of structural strategy for improving the debris brake performance. The stony debris flow was generated by releasing water discharge from a tank that contained gravel material. The efficiency of debris brake, debris accumulation pattern and its position parameters was used to evaluate the performance of the debris brake structure. The influences of debris brake slope, opening size and nonuniformity in deck opening size parameters that have not been studied before were investigated for different debris flow conditions. The results showed that the slope of debris brake was the most important factor on debris brake performance. The suitable slope was found to be a function of the debris flow velocity, and it can increase debris brake efficiency up to 10%. The analysis of the experimental data suggests the optimum opening size ratio (i.e., the ratio of opening size to median diameter of debris) smaller than or equal to one. Experimental data indicated that the nonuniformity in opening size of the debris brake cannot improve the debris brake efficiency.

This paper comparatively investigates the capability of 10 solo and hybrid Data Driven Models (DDMs) in predicting the pier scour depth. These models include Support Vector Machine (SVM), Adaptive ...

This is the first attempt to study the effect of debris on the scour at side by side pier and abutment. A large set of experimental tests was carried out at the hydraulic laboratory of Shahid Bahon...

Tailings are the reservoirs containing a high proportion of saturated silts that may be extremely difficult to sample in their undisturbed condition. This is mostly due to the fabric distu...

This paper presents a case study and numerical simulations of a corner of a deep excavation in Tehran supported by soldier piles and ground anchors. This study focuses on the differences between 2D...

A new moment connection for a steel beam to hollow structural section (HSS) and concrete-filled tube (CFT) columns using the through-plate technique is proposed. In the through-plate connection, all the demands of the beam are initially transferred to a vertical plate by in-plane action and are subsequently transferred to a column. Three full-scale interior planar connections are loaded cyclically under displacement control as per the AISI/AISC341-16 loading protocol. An axial compression force corresponding to 10% of the column axial capacity is applied to the column. The goals of the experimental study are as follows: (1) to evaluate the connection performance under cyclic loading and (2) to evaluate the connection components for extracting key design parameters. Square-shaped HSS sections with electric resistance welding are utilized for the column. To investigate the effect of concrete infill on the connection performance, the HSS column and one of the CFT columns are constructed using the same steel tube. The width-to-thickness ratio (b/t) for the corresponding specimens is 27, and another CFT specimen with a higher ratio of 34.5 is considered. In all the specimens, the plasticity is concentrated in the beam hinges, without any damage to the column or connection components. The proposed connection exhibits extremely high strength, stiffness, and ductility and is categorized as a rigid connection. Additionally, it exhibits stable cyclic behavior and high energy dissipation up to a story drift of at least 6% and satisfies the AISC seismic provisions as a special moment connection.

This study numerically investigates the side resistance of drilled shafts (bored piles) in sand using FLAC2D computer program. The results of the equations available in the literature are compared ...

Meandering rivers have a dynamic planform, which means that rivers move in radial direction with variable velocities. The movement velocities can be estimated from historical maps of specific river or using mathematical approach. There is not explicit method or suitable algebraic equation for estimation of river meander movement velocities. In this study, experiments were carried out in a laboratory flume, to develop novel equations to calculate meandering river movement velocities. We designated these empirical equations as the river resistance equations. The experiments were conducted with non-uniform, nonchosive sediment in a re-circulating flume with changeable slopes. The influence of bankfull discharge, bed slope and channel width on the meander movement velocities were discussed. Based on the experimental data, three novel empirical equations for prediction of Wx and Wexp and Wm were proposed. Moreover, the shuffled complex evolution (SCE) optimization algorithm was used to estimate the unknown parameters of the empirical equations. To validate SCE method, the result was compared with traditional multiple regression analysis. This comparison indicated that the SCE optimization algorithm outperformed the multiple regression analysis method in the empirical equations calibration.

An experimental program was conducted to investigate the effects of curing time and curing temperature on shear behavior of a sand-bentonite mixture. The specimens were cured at temperatures of 40°C, 60°C and 80°C for 1, 3 and 5 days under 100kPa, 500kPa and 1000kPa confinements. The results of consolidated undrained triaxial shear tests showed that an increase in temperature from 40°C to 80°C at 1, 3 and 5 days of curing increased the shear strength by 25%, 24% and 23%, respectively. Also, the increase in curing time from 1 to 3 and from 1 to 5 days at 80°C increased the shear strength of samples 12% and 24%, respectively. The failure of pre-cured samples occurred in lower strains as a result of more induced brittleness. Moreover, the secant modulus as well as the size of yield loci and critical state line’s slope increased by pre-curing. The application of thermal cycles resulted in increasing shear strength and experiencing a negative pore water pressure which shows a transition towards the quasi-structured behavior. The results of scanning electron microscopy (SEM) studies confirmed the increase in void ratio during thermal curing.

The paper presents a numerical analysis of pressuremeter test in unsaturated cohesive soils. In practice, pressuremeter is commonly expanded up to 10–15% cavity strains. At these strains, limit pressure is not usually reached, and its value is estimated by extrapolation. Accordingly, authors suggest using cavity pressure at 10% strain (P10) for the interpretation of pressuremeter test rather than limit pressure. At this strain, it is also assured that plastic strain occurs around the cavity, which is crucial for the interpretations. In unsaturated soils, the moisture at which a soil is tested has a noticeable influence on the pressuremeter cavity pressure, and consequently, on the magnitude of P10. In this paper, unsaturated soil behaviour has been captured by Barcelona basic model (BBM), and the influence of each BBM parameter on the P10 value is explored. Next, relative weight analysis technique is performed to investigate the relative importance of BBM parameters in prediction of P10. Artificial intelligence technique of genetic programming is used to develop a relationship to predict the P10 value in unsaturated soils from BBM parameters. Finally, the application of the proposed equation is shown through illustrative examples.

Excess pore water pressure (EPWP) measurements taken at different positions on a penetrating piezocone into a clayey soil are believed to play an important role in correlating to its chara...

Consolidation behavior of clays and sand–clay mixtures is an important topic in environmental geotechnics, thermal geostructures and disposal of hazardous wastes. The purpose of this paper is investigation of the changes in consolidation behavior of a sand–bentonite mixture due to the pre-curing at elevated temperatures. For this reason, 1:1 mixture of sand–bentonite was used to prepare samples 100 mm in diameter and 200 mm in height. The specimens were cured at 40, 60 and 80 °C for 1, 3 and 5 days under a constant confining pressure in a modified thermal triaxial cell. Then, consolidation behavior of the prepared samples which have been named as cured samples was investigated. The results show that the cured samples shifted from a reconstituted state to a quasi-structured one. A distinct yield stress was observed in compression curves of cured samples which was not apparent for reconstituted ones. The preconsolidation pressure of cured samples increased with increase in curing temperature and curing time. Also, the coefficient of consolidation and permeability increased as temperature increased, while both values decreased with an increase in curing time. Moreover, a number of specimens were tested under cyclic thermal paths which clearly proved change in behavior of cured samples to a structured one compared to the samples without thermal curing.

Dispersive soils, as one of the main categories of problematic soils, can be found in some parts of the earth, such as the eastern-south of Iran, nearby the Gulf of Oman. One of the most important factors enhancing the dispersive potential is the existence of dissolved salts in the soil water. The main objective of this study is to explore the influence of water salinity on the instability of a railway embankment due to rainfall infiltration. In order to achieve this goal, the embankment resting on a dispersive stratum is numerically modeled and subjected to transient infiltration flow. The effect of dispersion is simplified through variations in the soil-water retention curve with salinity. The measured water retention curves revealed that by omitting the natural salinity in the soil-water, the retention capability of the soil decreases; therefore, the unsaturated hydraulic conductivity of the soil stratum will significantly decline. According to the extensive decrease in the hydraulic conductivity of the desalinated materials, the rainfall cannot infiltrate in the embankment and the rainfall mostly runs off. However, in the saline embankment, the infiltration decreases the soil suction; and consequently, the factor of safety of the railway embankment decreases.

Does the overconsolidation ratio have any effect on the cone factor value used for determining the undrained shear strength? In order to find the answer, first the numerical modeling of a c...

The sand–bentonite mixture is used as the buffer layer in nuclear waste disposals. The buffer layer, as a non-permeable protective layer, is generally exposed to temperature gradients and the long-term subjection to temperature results in creep and more intact structure for the layer. In the present study, thermally induced structure and its effects on the isotropic compression behavior and volume change behavior of buffer layer are evaluated. Thermal consolidation tests were conducted using a modified triaxial cell capable of handling temperatures up to 90 °C. In order to investigate the effects of thermal gradients on the behavior of the mixture, saturated specimens were cured at constant temperatures of 40 °C, 60 °C and 80 °C, for time periods of 1, 3 and 5 days. Then, the consolidation tests were performed holding the curing temperature at a constant value up to end of the test. The results show that when the soil experiences higher temperatures for longer curing periods, the behavior of reconstituted soil is shifted from the reconstituted to a structured one which is an effect of induced creep in high-plasticity bentonite portion. Using the results of the tests performed in this study, a critical state-based constitutive model is proposed to simulate thermally induced volume change behavior of structured mixture. The capability of the proposed model is verified based on the experimental results and it is proved that the proposed model predictions are in good agreement with the experimental data.

Debris accumulation upstream of bridge piers is a destructive agent against the piers stability. In this study, the effect of debris geometrical characteristics on the local scour at piers group was investigated. A large set of experimental tests were conducted to investigate the effect of piers configurations, as well as, the shape, thickness, length, and position of debris on the dimensions of scour hole. The results showed that the debris with rectangular shape caused the most scour depth. In addition, among the different configurations of bridge piers, the group piers (2 × 2) demonstrated the largest scour hole. In this configuration, high complex interactions occurred among the flow, sediment and piers which generated strong horseshoe and wake vortices around the piers. The observations showed that the maximum depth of scour hole increases as the debris thickness increases. In addition, more the debris effective length, more the depth of scour hole. In the case of debris with rectangular shape, as the relative thickness of debris increased from 0.5 to 2.67, the depth of scour hole increased 67%, 80%, 84% and 104%, in single, side by side, tandem, and group piers (2 × 2), respectively. By increasing the distance of debris from the water surface, the depth of scour hole increased at the first, and then decreased when the relative submergence depth of debris became 0.46. In this condition, the debris acted as a collar, prevented the bed from scour. The measured scour depths were compared with common empirical formula, the formula were modified by considering the experimental results of this study.

Ground-borne vibrations resulting from the railway and road traffic have an adverse impact on the environment and nearby infrastructures. The focus of this study is on a specific part of the Tehran-Tabriz Railway located in the vicinity of Fath Highway, Tehran. In the investigated area, there are many residential buildings very close to the railway, and consequently, the train-induced vibrations make the people disturbed. After determining the soil layering and their properties using site investigation, the effect of geofoam trenches in mitigating train-induced vibrations was numerically investigated. The results showed that both the trench depth and width were important, especially at higher train speeds. Furthermore, the trenches installed further from the track performed better than the ones installed closer. In addition, the vibration levels before and after trench installation for different cross-sectional areas and slenderness ratios of the trench were numerically determined. The analyses are associated with the freight train speeds ranging from 40 km/hr to 160 km/hr. Also, the effect of several infill materials was investigated, and it was shown that softer infill materials perform better than harder ones. Finally, a procedure to adjust the results for different train types was proposed. Several graphs for design of geofoam trenches were proposed in this study.

Separation of the effects of initial horizontal stress and relative density on cone tip resistance in sandy soils has been a complicated issue for many years. In order to overcome this problem, a numerical modeling of CPT which has been verified by calibration chamber tests, has been used in this paper to achieve a reliable analytical solution. The analytical solution has resulted in two relationships for sleeve friction and cone tip resistance in terms of the initial conditions of sandy soil. Based on the presented solution, the initial horizontal stress and relative density can be determined according to CPT measurements.

Despite the various approaches in the literature adopted for analysing cone penetration test (CPT), determination of the initial horizontal stress and relative density of a sandy soil durin...

Understanding pile group behaviour is a critical key for geotechnical engineers. Nevertheless, there have been inadequate studies in the literature which tackle the many aspects of this important t...

Mixture of sandy soil and bentonite clay can be used to seal the sanitary landfills and prevent the spread of leachate. Over time, this mixture may be subjected to different landfill contaminants, including acidic pollutants and shear strength variations. The objective of this research was to study the effects of sulphuric acid pollutant with pH values of 7, 3 and 1 on the shear behaviour and strength of clean sand and sand mixed with bentonite clay using common consolidated undrained triaxial tests. The tests results showed that the presence of acid in the soil pore water changes the shear behaviour pattern of the soil. Acid pollutant decreases the clean sand shear strength. In sand–bentonite mixture, the presence of sulphuric acid with a pH of 3 results in an increase in the shear strength, and with a pH of 1, it results in a decrease. Acid pollutant decreases the elastic modulus of the soil and increases the negative pore water pressure generated during shear.

The use of shear wave velocity (V s) measurements as an in situ test for evaluation of liquefaction potential has increased substantially due to its advantages. Relatively large numbers of studies have been performed to establish the correlation between V s and liquefaction resistance (CRR) of clean sands. Usually, natural sands contain silt and/or clay, and previous studies have shown that both the amount of fines and their nature influence the values of CRR as well as V s. Therefore, the CRR–V s correlations may also be affected by fines content and type of sandy soils. However, effect of fines content and especially fines type of sandy soils on the correlation between V s and CRR is inadequately addressed in the literature. In this study, cyclic triaxial and bender element tests were conducted on samples of sand containing various amounts of different types of fines, and the effects of fines on the values of CRR and V s are investigated. The results show that G 0 and CRR reduce even when small amounts of fines are added to sand. Therefore, use of plasticity index (PI) of the fines fraction is better than the PI of the overall soil when trying to assess the effects of fines. Using obtained experimental data as well as the established semiempirical CRR–V s relationship, the CRR–V s correlation was developed for all the tested soils, and the effect of fines type on the correlation is also examined. Based on the results obtained in this study, CRR–V s correlation is affected by both the amount and the plasticity of the fines present in the sand, and this correlation is soil specific.

This paper suggests a new moment connection between steel beams and a reinforced concrete column (RCS). In this proposed connection, two parallel beams pass from both sides of the column and are welded to the cover plates surrounding the concrete column in the joint area. This detail provides two main advantages compared with previous constructions: first, both the beam and column are continuous in the joint area, which provides more reliable performance, and second, the force transfer occurs in such a manner that the cover plates are loaded in-plane and stress concentration is prevented in the connection components. Bar shear connectors were installed between the steel and concrete inside the cover plates to restrict sliding. The force transfer mechanisms and design procedure are described, and the seismic behavior of the proposed connection is studied in two experimental tests under cyclic loading. The test results showed that both specimens sustained 8% story drift with stable hysteretic loops and that the proposed connection is acceptable as a special moment connection. In addition, the test results demonstrated that the proposed design relationships were arranged properly such that the cover plates were maintained in the elastic phase, only slight cracks appeared in the column, and plastic hinges were formed in the beams in the vicinity of the column. Furthermore, to clarify the behavior and shear capacity of bar shear connectors embedded in a confined concrete, two push-out specimens were tested under monotonic loading.

Religious tourism was one of the most prosper types of tourism in the world in the past. Islamic tourism is mainly, a new interpretation of religious tourism that merges pilgrimage and recreational tourism. In order to achieve tourism development strategies, it is important to evaluate the satisfaction and loyalty of tourists in any tourist destination. Tourist satisfaction is important because it takes more tourists into the country and it has more foreign revenue for the country. The aim of this study is to investigate the effects of of traditional values ​​and Islamic values ​​on the satisfaction and loyalty of Muslim tourists. In this study, 387 foreign tourists were selected using Convenience sampling method. The present study is applied based on the aim and descriptive based on the method. To evaluate the research hypotheses, Structural Equation Modeling in Amos22 was used. The findings showed the effects of of quality value, social value, Islamic physical attributes and non-physical attributes on the tourists' satisfaction and loyalty of Muslim tourists. In the final section, applications, limitations, and suggestions for future researches were presented.

Effects of Anthropometric Factors on Foot Size in Normal Preschool Children of Iran Parvin- Dokht Bayat*; Mohammad Mehdi Ahmadi**; Mojtaba Moradi*** & Ali Ghanbari**** * Department of Anatomy, Arak Medical School, Arak University of Medical sciences, Arak, Iran. ** Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran. *** Department of Biology, Islamic Azad University, Hamedan Branch, Hamedan, Iran. **** Fertility and Infertility Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran. Abstract The growth pattern of children is affected by anthropometric dimensions. This study was aimed to investigate anthropometric factors related to growth of preschool children of a sample population in Iran. This study was performed in year 2011 on 1320 of 4–7 years old preschool children in Arak. To classify, body mass index (BMI), height and weight were recorded. The four contact points (head, back, buttocks, and heels) were maintained against the spine of the stadiometer during measurement. The head was positioned in the Frankfurt plane, and the sliding bar was lowered the crown of the head. Height was measured and recorded by the researchers. A pair of manual calibrated Seca scales was used to measure body mass in kilograms. The participants were least dressed in the uniform. We have classified BMI to four groups as group1, BMI with 10.75–15 and group 2, 3, 4 with 15.1–17 and 17.1–20, 20.1–22.5, respectively. Foot length was recorded as the distance from the posterior aspect of the heel to the most distal aspect of the longest toe. Foot length was measured with subjects standing upright using a foot board, a plastic device with calibrated lineation (in centimeters and millimeters). Analysis showed that sex neither affect on BMI nor foot measurements. The present findings contribute to the understanding of the effect of body mass on the structural development of the pediatric foot and musculoskeletal system. Excessive body mass seems to lead to increased foot length and width. KEY WORDS: Anthropometry; Body mass index; Iran; Obesity; Sex.

Geographic information systems (GIS) and remote sensing techniques are used as a decision support system to identify potential soil aquifer treatment (SAT) sites for groundwater recharge of Kerman aquifer, which is located in the southeast of Iran. These sites are identified using a single-objective multi-criteria analysis. To ensure technical feasibility, environmental sustainability, social acceptability and economical viability a number of criteria are considered for the site selection. The criteria selected for the different variables and acceptable ranges are based on standards published in national and international guidelines and technical documents. Multi-criteria evaluation was performed combining all produced thematic maps by means of the weighted index overlay method in order to select sites meeting all the criteria. The resulting map of this analysis shows potential sites are located in the north, southwest and southeast of the study area. Considering field observations, a potential site, which is located in the southwest of the study area, is proposed as the most suitable site for SAT. The result indicates that the study area has sufficient required suitable space for groundwater recharge with treated wastewater.

The paper presents a numerical finite difference model of self-boring pressuremeter test (SBPM) using FLAC software. Different cavity expansion theories in sand have been compared to the results of numerical analyses carried out in this study. Limit pressure is believed to be used as a key parameter for the estimation of soil parameters from pressuremeter tests. In practice, SBPM tests are conducted up to 10–15% cavity strains, and the strain level associated with the limit pressure state is not reached. Therefore, determination of limit pressure usually needs extrapolation. In this paper, the authors suggest to use cavity pressure at 10% strain (P 10) for the interpretation of in situ horizontal stress from SBPM test rather than limit pressure. For this purpose, more than 5000 numerical analyses of SBPM are carried out, and cavity pressures associated with 10% strain are deduced. Based on these extensive numbers of numerical analyses, a new relationship is established with the aid of genetic algorithm which correlates P 10 to soil parameters. The estimated values of P 10 from the proposed relationship are compared to a large database of measured ones obtained from laboratory and field results available in the literature. It was shown that the proposed relationship gives satisfactory predictions of P 10. A chart was established for deduction of the in situ horizontal stress using the proposed relationship. This method can be used as a complement to liftoff method which is not reliable for estimation of the in situ horizontal stress when soil disturbance occurs at cavity wall.

Ground vibration due to pile driving is a long-lasting concern associated with the foundation construction industry. It is of great importance to estimate the level of vibration prior to the beginning of pile driving, to avoid structural damage, or disturbance of building occupants. In this study, an axisymmetric finite-element model that utilises an adaptive meshing algorithm has been introduced, using the commercial code Abaqus, to simulate full penetration of the pile from the ground surface to the desired depth by applying successive hammer impacts. The model has been verified by comparing the computed particle velocities with those measured in the field. The results indicate that the peak particle velocity at the ground surface does not occur when the pile toe is on the ground surface; as the pile penetrates into the ground, the particle velocity reaches a maximum value at a critical depth of penetration. Some sensitivity analyses have been performed to evaluate the effect of soil, pile and hammer properties on the level of vibrations. The results show that increase in pile diameter, hammer impact force, soil–pile friction and reduction in soil elastic modulus can increase the peak particle velocity.

The application of the simplified method for evaluating the liquefaction potential based on shear wave velocity measurements has increased substantially due to its advantages, especially for microzonation of liquefaction potential. In the simplified method, a curve is proposed to correlate the cyclic resistance ratio (CRR) with overburden stress-corrected shear wave velocity ( V s1 ). However, the uniqueness of this curve for all types of soils is questionable. The objective of this research is to study whether the correlation between CRR and V s1 is unique or not. Besides, the necessity of developing the soil-specific correlations is also investigated. Based on laboratory test data, a new semi-empirical method is proposed to establish the soil-specific CRR– V s1 correlation. To validate the proposed method, a number of undrained cyclic triaxial tests along with bender element tests were performed on two types of sands. Similar experimental data for six other types of sands reported in the literature was also compiled. Applying the proposed method, soil-specific CRR– V s1 correlation curves were developed for these eight types of sands. It is shown that the correlation is not unique for different types of sands and the boundary curve proposed in the available simplified method can only be used as an initial estimation of liquefaction resistance. Finally, using the results of this study as well as previous ones, a chart is suggested to be used in engineering practice showing the conditions for which a detailed soil-specific CRR– V s1 correlation study needs to be performed.