Standart Penetration Test Correlation for Kocaeli,Turkey

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Standart Penetration Test Correlation for Kocaeli,Turkey Utkan Mutman 1, Murat Karadeniz 2 Abstract In any geotechnical design procedure, the fundemantal point to be initially clearified is the

1 Standart Penetration Test Correlation for Kocaeli,Turkey Utkan Mutman 1, Murat Karadeniz 2 Abstract In any geotechnical design procedure, the fundemantal point to be initially clearified is the characterization of existing soil profile at a site. Standard Penetration Test is considered one of the most common in-situ tests to evaluate the the soil parameters. The parameters to be determined in the ground examination sometimes cannot be obtained due to various reasons. In this case, from the correlations of Standard Penetration Tests, soil parameters are obtained. Up to the present day, many researchers have done Standard Penetration Test correlations. However; because they work in different areas, each correlation gives different results. In this study, the correlation was made between the values obtained from the Standard Penetration Test made in soil examinations which were done in Kocaeli (Turkey) and laboratory tests. In the first stage of this study, the fieldwork done in the ground examinations in Kocaeli /Turkey has been analyzed. The parameters obtained as a result of soil mechanics tests on disturbed and undisturbed samples taken from drills huddled together. These parameters are liquid limit, plastic limit, compression index, cohesion and internal friction angle. The SPT-N value obtained as a result of Standard Penetration Test done on each borehole and these soil parameters were matched. In the second stage of this study, by performing regression analysis between determined parameters, correlations were obtained between Standard Penetration Test and undrained shear strength (S u) of fine-grained soil. In this way, special Standard Penetration Test correlations for Kocaeli /Turkey were obtained. Soil parameters which could be obtained in this way are determined more accurately by Standard Penetration Test results. Keywords: Cohesion, In-situ Test, Soil Shear Strength Parameters,, Unconfined Compression Test. 1. INTRODUCTION The standard penetration test (SPT) is routinely used in the geotechnical engineering practice for in situ investigation of soil deposits. Due to the longtime and worldwide use of this test, comprehensive data have been accumulated in the past resulting in a number of SPT-based empirical correlations for clayed soils. In these correlations, the SPT blow count is used as a parameter for in situ characterization of field deposits. On the other hand, extensive information on the behavior of clayed soils has been obtained from laboratory tests on reconstituted and undisturbed samples. In these laboratory studies, cohesion is commonly identified as a principal factor influencing the deformation and strength characteristics of clays. Thus, in order to establish a correspondence between the field and laboratory parameters for soil characterization, the first step would be to provide a link between the penetration resistance and cohesion of clayed soils [1]. In order to find this correlation between cohesion of clayey soil and penetration resistance, studies have attempted to establish since the first implementation of the standard penetration test and numerous empirical correlations have been proposed in this direction in contemporary literature. On the other hand the proposed 1 Corresponding author: Civil Engineering Department, Kocaeli University, 41000, Kocaeli, Turkey. utkanmutman@gmail.com 2 Co-author:Civil Engineering Department,Kocaeli University, Kocaeli, Turkey,41000,karadenizmurat61@gmail.com 1

2 ICENS International Conference on Engineering and Natural Science, May 2016, Sarajevo correlations have usually been derived for the grounds located in a certain geographical area. In the case of using these correlations in different regions, results of the regional differences are affected. In the process of determining any parameter, it is important to reveal which range parameters can be changed using all available correlations and to do parameter selection considering all values with an engineering standpoint [2]. In Turkey, SPT is the field test most used in ground investigations. In most of the ground investigations, laboratory tests are done in the required soil layer. Therefore, the parameters required in the calculation of construction projects are used to be obtained by correlation. In this study, a new correlation between SPT penetration resistance and cohesion has been identified for Kocaeli/Turkey. In this way, by making a specific correlation for Kocaeli /Turkey, it will be ensured to obtain more accurate soil shear strength in construction activities Standart Penetration Test (SPT) Fletcher and Hanry A. Mohr standardized the penetration test for the first time with the hammer at 140 lb. being nailed on by dropping it from 30 in. using a sampling spoon [3]. "Standard Penetration Test (SPT), which was first come out in about 1927 and developed by "Raymond Concrete Pile Company" and introduced to the public by Terzaghi and Peck has been used in nearly 90 years [4]. SPT is widely used in North and South America, Australia, South Africa, India, Portugal, Israel, Turkey, Great Britain and Japan [5].Until now, various improvements have been achieved on this test [6]. In order to interpret the results of the SPT correctly, equipment used in the experiment and how the test has been done need to be known. The tools used for SPT varies more from country to country than the static penetrometer equipment. Many variables affect the validity and availability of SPT results [7].As a result of these variables, the measured penetration resistance (SPT-Nfield, Nf) may be excessively high or excessively low. In order to reduce the effects of these variables on geotechnical design and the determination of engineering properties of soils, SPT resistance corrections should be made. Within the frame of these corrections, geological load correction (CN), energy correction (CE), rod length adjustment (CR), boring diameter correction (CB), sampler sheath correction (CS) require to be used depending on instrumental details and the test experiment method [7]. Farrar stated that making CN correction in fine-grained soils, shallow cases would be normal but it was still controversial, especially for experiments performed in deep-set[8]. Although still controversial, CN correction for clay soils is applied in practice [9]. Therefore, this study has not taken into account the CN [10]. The correction shown in N60 is given by the following expressions [7]. C E.... N C C C N 60 = 60 Here N60 = Corrected SPT resistance according to the 60% of the theoretical free-fall energy mallet, Nf =Na =SPT resistance in the field. 2. METHODOLOGY B S R a To estimate the correlations needed N (SPT) and Laboratory Su, plasticity index (PI),sampling depths, boreholes diameter, drilling methods and other geotechnical properties of study area soil.in this study, ground investigation reports made in province of Kocaeli/Turkey were collected. SPT results in the report and cohesion values (Su) obtained from experiments performed in the laboratory on undisturbed soil samples taken during the ground investigation have been recorded. In order to correlate these data, first of all the necessary correction have been made in SPT resistance. For energy correction (CE) value of 45% was used; that is suitable for the conditions of Turkey. Because in Kocaeli/Turkey, boring are made in 100 mm diameter, drilling diameter correction (CB) was accepted as 1. Also because the SPT sampler is used for unshielded, sampler sheath correction (CS) was taken as 1. For the rod length correction (CR), values given in the table below were used in relevant depts. Table 1. Rod length correction (C R) (1) Depth (m) CR >

3 Standart Penetration Test Correlations for Kocaeli-Turkey Utkan Mutman,Murat Karadeniz In measured 113 SPT resistance (Nf), correction was performed using the first number formula. The collected physical and mechanicsl properties of Kocaeli fine-grained soils is presented in Table (2). Table 2. Geotechnical properties of studied fine-grained soil of Kocaeli Properties Min Max Ave. S.D Plasticity limit (PL) 12,9 39,5 20,89 20,89 Liquid limit (LL) 23 69,3 40,67 8,17 Plasticity Index (PI) ,95 5,09 Natural water content (w n) 5,5 38,8 21,75 5,59 Number of SPT (N field) ,71 8,13 N 60 2,25 27,08 11,13 5,23 Undrained shear strength (S u) ,5 72,48 23,8 To estimate undrained shear strength of fine- grained soils for the mentioned sites was investigated in two phases. In the first phase, only N (SPT) considered as independent parameter. İn the second phase the parameter of of natural water content (wn) and plasticity index (PI) considered as independent effective parameters, in addition to N (SPT) content. In the first phase, between Nf,N60 and Su linear regression analysis were performed. In this analysis first correlation coefficient was found and then the regression equation was obtained. The correlation coefficient (r) is 0.92,0.90 between Nf, N60 and Su respectively, r values close to 1.00 has been found. Because when the Nf value is zero, the Su value should also be zero, the regression equation was calculated as the Eq. (2,3) Su=5.604.N60 r=0,90 SD= 32,8 (2) Su=3,43.Nf r=0,92 SD= 30,47 (3) SD= Standart Deviation Figure 1. For this study, relationsips between SPT-N value and undrained shear strength of fine-grained soils İn the second phase the parameter of natural water content (wn ) and plasticity index (PI) considered as independent effective parameters, in addition to N (SPT) content. The correlations Eq.(4,5) were develop using multi linear regression between indepented parameters ( SPT-Nf,N60,wn,PI) and Su. Su= 1,54.N60+0,52. wn+2,93. PI r=0,94 SD=26,7 (4) Su= 3,47.Nf+0,06.wn-0,18.PI r=0,98 SD=6,12 (5) With regression analysis of data revealed that relationships in the second phase have beter correlation than first phase. (first phase: r = 0.92 and r = 0.90 for correlations based on Nfield and N60 respectively, second 3

4 ICENS International Conference on Engineering and Natural Science, May 2016, Sarajevo phase: r = 0.94 and r = 0.98 for correlations based on Nfield and N60 respectively that r is correlation coefficient). Correlations suggested in earlier research done on this topic and Su values obtained in the correlation suggested in this study results are given in Figure 2. 4 Figure 2. The comparison of the correlation, used in the study and Mutman and Karadeniz Eq.(2) Compared to previous correlations, correlations presented by Sirvikaya (2009), Terzaghi & Peck (1967) and İyisan & Ansal (1990) had conformity with present proposed correlations but correlation presented by Saglerat(1972), Nixon (1982), Kulhawy & Mayne (1990) had relatively large differences[2,4,11,12]. These differences could have been caused by soil physical as well as mechanical properties of each region. 3. CONCLUSION In the present study, between SPT-N and undrained shear strength for fine -grained soils correlations were obtained. Compared first phase and second phase result showed that considering other parameters such as water content (wn )and plasticity index (PI) in addition to SPT-N, increase the correlation coefficient of estimation. In order to obtain more realistic cohesion value with the N60 value, the use of natural water content and plasticity index is required for Kocaeli /Turkey. Soil properties and the tools used in the test, they differ from region to region.therefore, for different regions, when predicting soil parameter we must chose specific correlations that used in area or near. REFERENCES [1]. Cubrinovski, M. and Ishihara, K., Empirical correlation between SPT N-value and relative density for sandy soils, Soils and Foundations, 39(5): 61-71, [2]. Erol,A. O. and Çekinmez, Z., Geoteknik Mühendisliğinde Saha Deneyleri, Yüksel Proje Yayınları No: 14-01,2014. [3]. Sanglerat, G, The Penetrometer and Soil Exploration, Elsevier Publishing Co., Amsterdam, [4]. Terzaghi, K. and Peck, R.B., Soil Mechanics in Engineering Practice, John Wiley, New York, [5]. Durgunoğlu, H.T. and Toğrol, E., Penetration testing in Turkey: State-of-the-art report, Proceedings of the European Symposium on Penetration Testing, Stockholm, Sweden, p. 137, June [6]. Sivrikaya, O., Toğrol, E., Türkiye de SPT-N Değeri ile İnce Daneli Zeminlerin Drenajsız Kayma Mukavemeti arasındaki İlişkiler, İMO Teknik Dergi, , [7]. McGregor, J.A. and Duncan, J.M., Performance and use of the standard penetration test in geotechnical engineering practice, A Report of a study performed by Virginia Tech Center for Geotechnical Practice and Research, Virginia Polytechnic Institute and State University, October [8]. Farrar, J.A. and Chitwood, D., CME Automotic Hammer Operations, U.S. Department of the Interior Bureau of Reclamation Earth Sciences and Research Laboratory, Dam Safety Office, DSO-99-03, November 1999 [9]. Decourt, L, The Standard Penetration Test: State-of-the-Art-Report, Norwegian Geotechnical Institute Publication, 179, Oslo, Norway, 1990 [10]. Sivrikaya, O., Toğrol, E., Relations between SPT-N and q u, 5th International Congress on Advances in Civil Engineering, p , Istanbul, Turkey, [11]. Nixon, I.K., Standard penetration test: State-of-the-art report, Proceedings of the 2nd Europen Symposium on Penetration Testing, Amsterdam, Netherlands, 3-21, May [12]. Kulhawy, F.H. and Mayne, P.W., Manual on estimating soil properties for foundation design, Electric Power Institute, Palo Alto, CA,

5 Standart Penetration Test Correlations for Kocaeli-Turkey Utkan Mutman,Murat Karadeniz BIOGRAPHY Name Surname: Murat Karadeniz Place and Date of Birth: / Trabzon EDUCATION: B.Sc.: 2010, Karadeniz Technical University, Civil Engineering Department M.Sc: 2015, Kocaeli University, Institute of Natural Science of Civil Engineering Department PROFESSIONAL EXPERIENCE: 2010~2012 : Civil Engineer of Eksı Group of Companies 2012 ~ : Research Assistant at Kocaeli University 5

SITE INVESTIGATION Validation and Interpretation of data

SITE INVESTIGATION Validation and Interpretation of data Dr. G.Venkatappa Rao The Impact 1 The Need To determine the type of foundation To assess bearing capacity/settlement Location of Ground water table,issues