EFFECT OF SOIL TYPE LOCATION ON THE LATERALLY LOADED SINGLE PILE

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 12, December 2018, pp , Article ID: IJCIET_09_ Available online at aeme.com/ijciet/issues.asp?jtype=ijciet&vtype= =9&IType=12 ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EFFECT OF SOIL TYPE LOCATION ON THE LATERALLY LOADED SINGLE PILE Dr. Laith J. Aziz Assistantt Professor, Civil Engineering Department, Faculty of Engineering, University of Kufa, Najaf, Iraq Waseem Al-Baghdadi Lecturer, Civil Engineering Department, Faculty of Engineering, University of Kufa, Najaf, Iraq Dr. Tawfek Sheer Ali Lecturer, Structures and Water Resources Department, Faculty of Engineering, University of Kufa, Najaf, Iraq ABSTRACT This study presented an experimental work to examine the behavior of a single pile installed in three different types of soil when it is subjected to lateral load. The experimental work was divided into six tests to study the effect of soil type location on the lateral displacement of the pile by changing soil type placement surrounding the pile, each layer was taken of a thickness equals to 60 mm and the length of pile is 150 mm. A steel box with dimensions of width (w = 300 mm), length (L = 600 mm and height (H = 1000 mm) was used to perform a laboratory tests. The main conclusions were that the largest lateral displacement corresponding to minimum lateral load was when the sand soil is placed near the surface followed by silt and clay, also, the lateral displacement decreases and the lateral load which can be resisted by the pile increases when the fine soil enclosed the upper first third of the pile. The ideal placement of soil layers was for silt, sand and clay is placed subsequently (Model 6) which has the lateral displacement as a minimum value corresponding to maximum applied lateral load. The results of ideal model (Model 6) were verified with the results obtained by PLAXIS software, the percentages of lateral displacement obtained from PLAXIS 3D software to the experimental work was 88.8% (ultimate displacement from experimental work is 8 mm and from PLAXIS is 9 mm). Keyword: Laterally Loaded Pile, Lateral Pile Capacity, Soil Type Location editor@iaeme.com

2 Effect of Soil Type Location On The Laterally Loaded Single Pile Cite this Article: Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali, Effect of Soil Type Location On The Laterally Loaded Single Pile, International Journal of Civil Engineering and Technology (IJCIET) 9(12), 2018, pp INTRODUCTION Deep foundation (Piles) are usually used when the transmitted load of the structure is heavy such as the surface soil do not capable to bear, so the piles can be embedded to the lower soil or rock. When designing piles for these type of buildings the vertical loads are not the only criteria have to be checked, lateral loads which generated from many agents like: earthquake or wind loads- is also an important criterion which have to be checked carefully. Moreover, piles are also exposed to high value of lateral loads in marine and offshore structures due to sea-wave action. The behavior of laterally load piles depends on many factors like; stiffness of both pile and soil, the resistance of mobilization of the surrounding soil, boundary condition of piles (the state of its connection with their structure). Duration and frequency of load application, the type of the surrounding soil and the existence of more than one type of soil. In this work, a laboratory steel model and some accessories where used to perform a series of tests for a single steel pile embedded in three different soil layers (sand, silt and clay) with the same thickness to study lateral load-lateral displacement behavior. The location of each soil layer were changed sequentially to analyze the effect of change the locations of these soil layer types on the behavior of the pile subjecting to lateral load. Many studies have been published suggesting methods to predict the behavior of single pile when subjecting to lateral loads. Subgrade Reaction Method is considered one of these methods, the pile in this method is considered as a flexible beam on elastic foundation, it simulates the soil by a series of elastic and closely spaced but independent springs and layered foundation could be considered, this method presents a simple method to deal with piles subjected to lateral load, (Davisson and Gill, 1963 and Dai and Chen, 2007). The response of pile could be calculated by solving the differential equations by finite difference or finite element methods of the deflection curve (Poulos, 1971a; Poulos and Davis, 1980). Basing on elastic behavior of soil, some analytical studies were submitted by (Davisson and Gill, 1963; Lee and Karunaratne, 1987) to study the influence of pile length, thickness of upper layer, and the stiffness ratio for adjacent layers on the response of the pile.[14,15] A series of three-dimensional finite element formulas were conducted by (Brown and Shie, 1990a), (Brown and Shie 1990b), (Brown and Shie, 1991) and (Trochanis et al., 1991) to predict the behavior of laterally loaded single pile and pile group. The soil was simulated by an elastic-plastic constitutive relationship. An interface elements were also used in the contact area between pile and soil to represent the action in this area like separation and slippage. Moreover, a p-y curves were derived by from (Finite Element Method (FEM) data to make a comparison between FEM results and the results which gotten from the empirical design procedure. 2. MATERIALS AND TESTING 2.1. Types of Soil Used Three different types of soil were used in this study (sand, clay and silt). The sieve analysis is carried out according to ASTM (D ) to achieve the requirements of the Unified Soil Classification System (USCS). Table 1 shows the properties of soil used editor@iaeme.com

3 Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali 2.2. Laboratory Models A steel box with dimensions of width (w = 300 mm), length (L = 600 mm and height (H = 1000 mm) was used to perform a laboratory tests on the soil. The model of pile was also made from square cross sectional steel material of dimension (B = 10 mm) and length of (200 mm), the embedded length of the pile in the soils is the same in all tests and equal to (l = 150 mm). The steel box and pile model were shown in Fig. 1 and 2 respectively. Table 1 The properties of soils used Property Sand Clay Silt Uniformly Coefficient, C u Curvature Coefficient, C c Specific Gravity, G s Dry Unit Weight, γ d (kn/m 3 ) Optimum Water Content, (%) Liquid Limit, L.L, (%) Plasticity Index, PI (%) Cohesion (c), (kn/m 2 ) Angle of internal friction, ( o ) Soil Classification (USCS) SP CH SM Figure 1 Steel box used in laboratory tests 2.3. Soil and Pile Installation Procedure To simulate the soil layers' condition in the field, the soil layers were put in the box and compacted with the standard proctor hammer to achieve relative density of 80%. To estimate the unite weight of each soil layer in the box, the weight of soil which fill the required volume was collected and put in the box then it is compacted to reach 80% relative density. The pile model then pushed into the soil layers by hammering with proctor hammer until reach to depth of 150 mm as shown in Fig Model Setup and Accessories To investigate the lateral displacement of the pile due to the lateral load, a dial gauge with sensitivity of (0.01 mm) was attached to the pile head to measure the lateral movement of the editor@iaeme.com

Effect of Soil Type Location On The Laterally Loaded Single Pile pile.

corresponding to each load increment was recorded. The nonlinear loaddisplacement curve was drawn by the incremental manner of load application with continuous recording of dial gauge readings.

Figure 2Steel pile model Figure3Soil and pile installation 2.5.

4 Effect of Soil Type Location On The Laterally Loaded Single Pile pile. The pile was subjected to a lateral load through a pulley system having a flexible wire attached to a loading pan, the load was applied gradually with a (20 N) increment and the dial gauge reading corresponding to each load increment was recorded. The nonlinear loaddisplacement curve was drawn by the incremental manner of load application with continuous recording of dial gauge readings. It is worthy to mention that there is no distance between the steel weir and the ground surface i.e. (e=o).the final setup of model and other accessories are shown in Fig. 4. Figure 2Steel pile model Figure3Soil and pile installation 2.5. Test Procedure The experimental work was divided into six tests to study the effect of soil layer location on the lateral displacement of the pile, from the changing soil layer location can be found the ideal soils location surrounding the pile, each layer was taken of a thickness equals to 60 mm. The soil placement in the test box were put such as the sand layer was remained at the top (surface layer) for the first and second models, while other two layers (silt and clay) were changed in succession, in the same manner the clay layer was at the top for the third and editor@iaeme.com

Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali fourth models, eventually, in the last two models the silt layer was placed at top as shown in Fig. 5.

5 Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali fourth models, eventually, in the last two models the silt layer was placed at top as shown in Fig. 5. As presented in the previous section, the height of testing box is 300 mm and the embedded length of pile in soil is 150 mm, that means the pile end in all tests was placed at the middle of the third layer. The remaining depth of the testing box (12 cm) was remained a sandy soil for all testing as shown in Fig RESULTS AND ANALYSIS 3.1. Models with Sand Layer at Surface Figure 7 shows the load-displacement relationship for the first and second model, it is seen that for the range of load from 0.0 N up to 60 N the two curves goes closely to each other, but when the value of load exceeding 60 N the curve of the second model (Sand, Clay and Silt) suddenly started to go far away from the relationship of model 1 revealing high values of load with smaller displacement. From these curves, it can be seen that if the clay layer near the surface (model 2), the displacement is smaller with the comparison of model 1 in which the silt near the surface at the same lateral load Models with Clay Layer at Surface In this section, the results of third and fourth models will be discussed. In these models clay layer will still at the surface layer, while the sand and silt layers will be replaced respectively. Figure 8 describes the trend of load-displacement curves for these models. Similarly, to previous figure, the two curves show huge identification in values of load and displacement up to 60 N and 4 mm, after this specified point, the curve of the third model (clay, silt and sand) showed a steadily divergence form model 4. From the figure, it can be concluded that it is better the silt layer be beneath the clay layer than sand layer editor@iaeme.com

6 Effect of Soil Type Location On The Laterally Loaded Single Pile model 1 model 2 L a te ra l L o a d (N ) Lateral Diaplacement (mm) Figure 7Load-lateral displacement relationship for models 1 and model 3 model 4 L a te r a l L o a d (N ) Lateral Diaplacement (mm) Figure8Load-displacement relationship for model 3 and Models with Silt Layer at Surface The results of the last two models (5 and 6) are shown in Fig. 9. The behavior of the relationships of these modes are different from the other models because they are diverging from the second loading step and the relationships seems as a linear up to 125 N. The lateral displacement corresponding to maximum load for the two models are smaller with the comparison of other models and the failure appear at larger load. It is very important to visualize that model 6 represents ideal soil layers' placement to get larger lateral applied load with minimum lateral displacement editor@iaeme.com

7 Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali 3.4. Results Analysis To study the behavior of load-displacement relationships for all models, the results are drawn as in Fig. 10. It can be seen that models 6, 5 and 3 give a maximum applied load with minimum displacement respectively, that means when the fine soil located near the surface where the load applies, the pile can resist larger load and the displacement be at a smaller amount, also, it can be visualized that although model 2 suffering more lateral displacement values comparing with model 5, but they had the same ultimate load capacity and model 6 exposed the highest resistance followed by model 3, while model 1 have the lowest ultimate load capacity model 5 model 6 L a te r a l L o a d (N ) Lateral Diaplacement (mm) Figure 9Load-displacement relationship for model 5 and 6 Lateral Load (N) model 1 model 2 model 3 model 4 model 5 model Lateral Diaplacement (mm) Figure 10 Load-displacement relationship for all models editor@iaeme.com

flow and stability of geotechnical problems can be made using 3D Finite Element Method.

8 Effect of Soil Type Location On The Laterally Loaded Single Pile 4. VERIFICATION EXPERIMENTAL RESULTS WITH PLAXIS 3D SOFTWARE PLAXIS package is a numerical software that has been published as a specialist geotechnical program since 1987, the analysis of deformation, flow and stability of geotechnical problems can be made using 3D Finite Element Method. PLAXIS 3D software was used to verify the results of model 6 which was gives an ultimate capacity with smaller lateral displacement. The dimension and soil layers were modeled in PLAXIS as in laboratory model. Figures 11, 12 and 13 show the modelling of model 6 in PLAXIS. Same load increment (20 N) was used for the load phases to compare the experimental results of lateral displacement corresponding to load in PLAXIS. The behavior of load-displacement relationship of numerical results diverges to experimental results after 200 N loading slightly, it can be seen that is a strong correlation (R 2 ) between the numerical and experimental results because it was founded as 97.4%. The ratio of lateral displacement obtained from PLAXIS 3D software to the experimental work is 88.8% (ultimate displacement from experimental is 8 mm and from PLAXIS is 9 mm). The numerical results obtained by PLAXIS and experimental work for model 6 are drawn in Fig. 14. Figure 11Modeling of model 6 in PLAXIS as a borehole Figure 12 Modeling of model 6 in PLAXIS as a shading editor@iaeme.com

9 Dr. Laith J. Aziz, Waseem Al-Baghdadi and Dr. Tawfek Sheer Ali 300 L a te r a l L o a d (N ) Experimental PLAXIS Lateral Diaplacement (mm) Figure 13 Lateral displacement ( m for 200 N loading) Figure 14 Load-displacement relationship for experimental and PLAXIS of model 6 5. CONCLUSIONS This study presented an experimental work to investigate the behavior of a single pile embedded in three different types of soil when it is subjected to lateral load, the relationships between lateral load and lateral displacement is studied and the ideal location of soil layers subsequently also investigated (6 models). The results of ideal model (Model 6) were verified with the results obtained by PLAXIS software. The following conclusions can be drawn from the study: When the sand soil is placed near the surface followed by silt and clay. The lateral displacement is the highest largest lateral displacement corresponding to minimum lateral load was when the sand soil is placed near the surface followed by silt and clay. The behavior of lateral load-lateral displacement relationship when the soil layers' placement is (sand, clay and silt) is closely the same when the soil layers placed as (silt, clay and sand). When the soil layers' locations as (clay, silt and sand) is nearly the same when the soil layers placed as (silt, sand and clay). The lateral displacement decreases and the applied lateral load which can be resisted by the pile increases when the fine soil enclosed the upper first third of the pile. Among the six models which were presented in the study when the placement of silt, sand and clay subsequently (Model 6), the lateral displacement is a minimum value corresponding to maximum applied lateral load. It can be considered Model 6 is an ideal placement of soil layers'. The correlation (R 2 ) between the numerical results by PLAXIS 3D software and experimental results for Model 6 reaches to 98.4% and the percentages of lateral displacement obtained from PLAXIS 3D software to the experimental work is 88.8% (ultimate displacement from experimental work is 8 mm and from PLAXIS is 9 mm) editor@iaeme.com

10 Effect of Soil Type Location On The Laterally Loaded Single Pile REFERENCES [1] Davisson M.T. and Gill H.L. (1963). Laterally Loaded Piles in a Layered Soil, Jl. of Soil Mech.& Found. Div., ASCE, 89(3): [2] Dai, Zihang, Linjing CHEN (2007) Two numerical solutions of laterally loaded piles installed in multi-layered soils by m method, Chinese Journal of Geotechnical Engineering, 29(5), pp [3] Poulos, H. G. (1971a) Behavior of laterally loaded piles. I: single piles Journal of the Soil Mechanics and Foundations Division, ASCE, 97(5), pp [4] Poulos, H. G., and E. H. Davis (1980) Pile foundation analysis and design John Wiley & Sons, Inc, United States. [5] Lee, S. L., Kog, Y. C. & Karunaratne, G. P. (1987), Laterally loaded piles in layered soil. Soils, Fdns. 27, No. 4, [6] Brown and C.-F. Shie., Numerical experiments into group effects on the response of piles to lateral loading, Computers and Geotechnics, 10: , 1990a. [7] Brown and C.-F. Shie. Three dimensional finite element model of laterally loaded piles, Computers and Geotechnics, 10:59 79, 1990b. [8] Brown, D. A. & Shie, C. F. (1991), Modification of p-y curves to account for group effects on laterally loaded piles, Proc. Congress Geotech. Engng. Div. 1, Am. Soc. Civ. Engrs., [9] Trochanis, A. M., Bielak, J. & Christiano, P. (1991), Three-dimensional nonlinear study of piles, J. Geotech. Engng., Am. Soc. Civ. Engrs 117, No. 3, [10] ASTM D422-63, 2007, Standard Test Method for Particle Size-Analysis of Soils. [11] ASTM D698, (2007), Standard Test Methods for Laboratory Compaction Characteristic of Soil Using Standard Effort. [12] ASTM D3080, (2007), Standard Methods for Direct Shear Test of Soils under Consolidated Drained Condition. [13] ASTM D854-05, (2007), Standard Test Method for Specific Gravity of Soil Solids by Water Pycnometer. [14] Kadhim Naief Kadhim and Ghufran A. (The Geotechnical Maps For Gypsum By Using Gis For Najaf City (Najaf -Iraq) (IJCIET), Volume 7, Issue 44, July-August 2016, pp [15] A.A. Al-Khalidy and.a. N. Kadhum &K.N.Kadhim Application Of Ground Penetrating Radar To Determine The Subsurface Features Of The Project Of Shams Alshmoos Hotel Building In Al-Najaf Alashraf, Iraq. (IJCIET), Volume 9, Issue 6, (June 2018) editor@iaeme.com

Evaluation of short piles bearing capacity subjected to lateral loading in sandy soil

Evaluation of short piles bearing capacity subjected to lateral loading in sandy soil [Jafar Bolouri Bazaz, Javad Keshavarz] Abstract Almost all types of piles are subjected to lateral loads. In many cases,