Home The behavior of piled rafts in soft clay: Numerical investigation
Article Open Access

The behavior of piled rafts in soft clay: Numerical investigation

  • Mostafa Elsawwaf , Marwan Shahien , Ahmed Nasr and Alaaeldin Magdy EMAIL logo
Published/Copyright: July 11, 2022
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Journal of the Mechanical Behavior of Materials
From the journal Journal of the Mechanical Behavior of Materials Volume 31 Issue 1

Abstract

This research aims to investigate the applicability and performance of piled rafts in soft clay. This aim has been achieved by studying how the pile length, pile number, raft-soil relative stiffness, and presence of a sand cushion beneath the raft would affect piled raft settlement, differential settlement, and load sharing. Piled rafts have been numerically simulated using PLAXIS 3D software. Experimental testing results were used to verify the numerical simulation. The portion of the load carried by the piles to the total applied load was represented by the load sharing ratio (GPR). The results indicated that with increasing pile length and number, settlement and differential settlement decreased. It was also noticed that with increasing raft-soil relative stiffness, the differential settlement decreased. The GPR decreased with increasing thickness and relative density of the sand cushion, whereas it increased with increasing pile length and number. This increase in GPR was 13.7, 36, and 58% with an increase in pile length to diameter ratio from 10 to 30 for the number of piles 4, 9, and 16, respectively. Additionally, the raft-soil relative stiffness was observed to have a marginal effect on the GPR.

Keywords: piled rafts; load sharing ratio; raft-soil relative stiffness; soft clay; sand cushion; numerical modeling

1 Introduction

In piled rafts, the bearing behavior, pile capacity, total settlement, differential settlement, and load sharing behavior are considered crucial parameters for design. Several researchers have studied the bearing behavior [1,2], pile capacity [3], total settlement [4–6], and differential settlement [7–9] of piled raft foundations. Lee et al. [1] found that using a limited number of piles in strategic locations will improve the bearing capacity of the raft. Karkush et al. [3] used standard penetration test results and MATLAB software to predict the bearing capacity of driven piles and found there is a 30% difference between the calculated and predicted bearing capacity of driven piles. Cho et al. [4] concluded that the total settlement was reduced effectively by increasing the pile spacing at the same pile lengths. El-Garhy et al. [7] conducted an experimental program in sandy soil to assess how the raft-soil relative stiffness would affect the behavior of piled rafts. They noticed a major effect on decreasing the differential settlement due to increasing the raft-soil relative stiffness. Elwakil and Azzam [8] found that piles as settlement reducers in sandy soil are very useful in decreasing differential settlement. They also noted that the raft contact pressure increases with decreasing pile length. Mali and Singh [9] studied piled raft behavior using 3D finite element modeling in stiff clay. They found that when the spacing of the piles increases, the differential settlement decreases up to a particular spacing, after which it increases. Thoidingjam and Devi [10] studied how the raft rigidity would affect the ultimate capacity and total settlement of piled rafts in organic clay. They found that higher rigidity gives higher load and lesser settlement of piled raft system. For the term of load sharing, Karkush and Aljorany [11] reanalyzed a piled raft under construction in the Southern part of Iraq using analytical equations and numerically by SAFE 12 software. They noticed a change in the load sharing of the constructed piles due to redistribution of the applied loads on the stiffer piles and the raft. Davids et al. [12] indicated that the load carried by the raft is about 20:50% of the total applied load. Leung et al. [13] stated that the raft contact pressure changed from 25 to 50% of the building stress. Abdel-Fattah and Hemada [14] indicated that the raft load is about 30:60% of the applied load depending on the soil condition. This portion increases with decreasing pile length and increasing pile spacing. On the other hand, Hoang and Matsumoto [15] reported from experimental tests that the load shared between the raft and piles for spacing 3D is clearly like that for spacing 6D. Hemsley [16] obtained that the soil can carry loads up to 50% of the total load by raft contact pressure. Many contributions to the concept of piled rafts have been conducted in Germany including experiments, field measurements, and numerical studies during the 1980s and 1990s. Piled rafts have been used frequently in Frankfurt stiff clay to support heavy high-rise buildings [17,18]. Although there are enormous studies on piled rafts, there is a scarcity of parametric studies for piled rafts in soft clay. Therefore, the effect of pile length, pile number, raft-soil relative stiffness, and the presence of a sand cushion beneath the raft have been investigated in this study.

1.1 Research significance

Soft soils are found in many regions in Egypt such as the industrial zone in Port Said, in which the soft clay extends up to the depth of 60 m. As reaching the bearing layers in very deep soft soils is difficult and uneconomic, the floating piles would be appealing to reduce settlement and enhance the bearing capacity. Hence, the main objective of this research is to investigate the applicability and performance of using piled rafts in soft clay.

1.2 Testing equipment

Remolded kaolinite was used to prepare the soft clay deposit. Kaolinite clay is usually applied in laboratory investigations and physical model testing, as well as in fundamental studies of soil behavior as mentioned by Abdelrahman and Elragi [19]. The soft clay was prepared according to Ilyas et al. [20]. The raft was a square steel plate with a length of 200 mm and the piles were steel hollow tubes with a length of 250 mm, an outer diameter of 10 mm, and a thickness of 1.3 mm. The plate had nine holes with 10 mm diameters. The top head of each pile was provided with a solid tube with a sufficient length to achieve a 10 mm length inserted into the hollow tube and a screwed length to connect the pile to the raft through a nut to ensure a rigid connection. The test chamber was a cube with edges of 600 mm and made from steel plates. The test chamber and raft dimensions were selected to ensure no effect on the failure mechanism of soft soils according to Prandtl [21]. A load cell was used to measure the applied load. To measure the settlement, four linear variable differential transformers (LVDTs) with 0.001 mm accuracy were placed on raft corners. The LVDTs average value was calculated to represent the total settlement of the piled raft. Strain gauges were attached to pile heads to measure the elastic strains developed and hence the axial forces of piles were calculated. The test chamber and instrumentations used in the present study are presented in Figures 1 and 2.

Figure 1 Test chamber and instrumentations (dimensions in mm).
Figure 1

Test chamber and instrumentations (dimensions in mm).

Figure 2 The driving process and instrumentation locations.
Figure 2

The driving process and instrumentation locations.

2 Finite element modeling

2.1 Meshing and boundaries

In the present study, the foundation was loaded by a uniform load (q) of 80 kPa. As shown in Figure 3, the soil mass dimensions were the same as the dimensions of the test chamber. The model lateral soil domain limits were constrained against horizontal translation but allowed vertical soil translation. The bottom soil boundary was selected to be three times the raft width according to Yılmaz [22]. The model mesh size was fine but around the working zone it was very fine to ensure solution accuracy.

Figure 3 Meshing and boundaries.
Figure 3

Meshing and boundaries.

2.2 Constitutive modeling

The hardening soil (HS) model used in this study is a sophisticated constitutive model that can simulate both stiff and soft clays. The HS is a development of Duncan and Chang’s hyperbolic model [23]. HS model depends on plasticity theory with soil dilatancy, and a yield cap behavior modeled. The HS model employs a work-hardening plasticity technique to represent soil loading in shear. As the plastic shear strain increases, the inner yield surface expands to meet a Mohr–Coulomb failure surface on the outside. As the HS model uses the hyperbolic stress–strain curve and controls stress level dependency, it offers an advantage over the Mohr–Coulomb model. The raft was modeled as a plate element and the piles as embedded beams. The embedded beam was defined as a circular tube and the connection with the raft was rigid. The analysis included four stages, the initial stage, pile installation stage, raft stage, and loading stage. In the past numerical research, the stress change because of pile installation was neglected [24,25]; however, the installation method of piles affects the condition of stress. The pile installation method (driving or boring), type of soil (sand or clay), and condition of the soil (soft clay or stiff clay) affect the stress change in the soil, so driven piles were used in the present study to match the experimental work.

2.3 Model validation

The ability to validate the experimental model is a key feature of employing numerical software to create simulations. The properties of soft clay and sand at different relative densities were obtained from experimental testing except for dilatancy angles and the Poisson’s ratios. The dilatancy angles (ψ) were calculated using the equation given by Schanz and Vermeer [26] and the Poisson’s ratios (υ s) of the used sand at different relative densities were obtained using the charts given by Dutta and Saride [27]. The clay secant stiffness ( E 50 ref ) and unloading/reloading stiffness ( E ur ref ) were obtained from the stress–strain curve (Figure 4a), whereas tangent stiffness for oedometer loading ( E oed ref ) was obtained from the stress–strain curve of odometer test. For the sand cushion, ( E 50 ref ) was obtained from the triaxial test results (Figure 4b), whereas the ( E ur ref ) and ( E oed ref ) were obtained from Eqs. (1) and (2), the program default. The material properties of the soft clay and sand are summarized in Table 1. The Young’s modulus and unit weight of raft and piles, obtained from the datasheet of the manufacturing company, are summarized in Table 2. Figure 5 shows the present study results in comparison with the results of the experimental model. As shown, the results of the present study were in a reasonable level of agreement with the experimental stress-settlement curve of the piled raft and represent the variation of pile load (Pp) with the settlement.

(1) E ur ref = 3 E 50 ref ,

(2) E oed ref = E 50 ref .

Figure 4 Stress–strain curves for used materials. (a) Stress-strain curve of soft clay, and (b) stress-strain curve for sand.
Figure 4

Stress–strain curves for used materials. (a) Stress-strain curve of soft clay, and (b) stress-strain curve for sand.

Table 1

Soft clay and sand cushion properties

Soil parameter Soft clay Sand cushion
Material model HS model HS model
Drainage type Undrained Drained
Saturated bulk density (kN/m3) 18.65 18.80, 19.30, 19.50
E 50 ref (kN/m2) 1,600 50,000, 62,000, 75,000
E oed ref (kN/m2) 1,500 50,000, 62,000, 75,000
E ur ref (kN/m2) 4,200 150,000, 182,000, 225,000
Power (m) 1.0 0.5
Undrained cohesion (kN/m2) 16 −
Angle of internal friction, ϕ° − 36, 38, 40
Relative density, Rd − 60%, 70%, 80%
P ref (kN/m2) 100 100
Table 2

Raft and pile properties

Raft Pile
Material model Plate Embedded beam
Unit weight (kN/m3) 78.5 78.5
Young’s modulus (kN/m2) 200.0 × 106 200.0 × 106
Figure 5 Comparison of numerical and experimental results for piled raft system.
Figure 5

Comparison of numerical and experimental results for piled raft system.

2.4 Parametric study

The total settlement, differential settlement, and load sharing behavior of the piled rafts were studied with the variation of pile length, pile number, raft-soil relative stiffness, thickness, and relative density of the sand cushion (Table 3). The pile arrangement is presented in Figure 6.

Table 3

Parametric analysis

Parameter Value
Pile length, Lp/pile diameter, dp 10, 15, 20, 25, 30
Pile number 4, 9, 16
Raft thickness 2, 4, 10 mm
Corresponding raft-soil relative stiffness 0.08, 0.70, 10.43
Sand cushion thickness, Hc/pile diameter, dp 1, 2, 3, 4, 5
Figure 6 Pile arrangements (dimensions in mm).
Figure 6

Pile arrangements (dimensions in mm).

The results were plotted to indicate the effect of studied parameters on the settlement reduction ratio (SR), differential settlement reduction ratio (Sdiff), and load sharing ratio (GPR). The SR is the ratio of maximum settlement of piled raft to the maximum settlement of raft. The differential settlement is expressed in Eq. (3). The SR and Sdiff are calculated by Eqs. (4) and (5). The GPR is the proportion of total pile load (Pp) to total applied load (Ppr). GPR is introduced to obtain the percentage of load carried by piles and raft individually. The load carried by piles (Pp) is calculated by summing the load at their heads. The expression for GPR is given in Eq. (6). The raft-soil relative stiffness (K rs) is calculated using Eq. (7), which has been given by Brown [28], where E r is the modulus of elasticity of the raft, υ s is the Poisson’s ratio of soil, G s is the shear modulus of soil, t is the raft thickness, and B r and L r are the raft dimensions.

(3) Differential settlement  = Max . settlement of the raft – Min . settlement of the raft,

(4) SR = Maximum settlement of piled raft Minimum settlement of raft ,

(5) Sdiff = Differential settlement of piled raft Differentail settlement of raft  ,

(6) GPR = Pp Ppr ,

(7) K rs = ( 1 − υ s ) × E r 2 G s × 4 B r 3 π L r t L r 3 .

3 Results and discussion

3.1 Effect of pile length (Lp) and number (Np)

To analyze the effect of Lp and Np, simulations were carried out on piled rafts with Lp/dp of 10, 15, 20, 25, and 30, for Np of 4, 9, and 16, and piles were spaced at Sp = 6dp. Figures 7–9 present the effect of Lp/dp and Np on SR and Sdiff at different K rs values. The results show that SR and Sdiff decreased with increasing Lp/dp and Np for every K rs value. The decrease in SR and Sdiff was a result of increasing the skin friction of piles by increasing Lp/dp and Np. Additionally, the decrease of SR was obtained to be similar at the same Np and Lp/dp for different K rs values (e.g., piled raft with Lp/dp of 25 and Np of 9 at K rs of 10.43 caused SR equal to 0.614 and piled raft with the same Lp/dp and Np at K rs of 0.7 caused SR of 0.58). In comparison with the Sdiff, with increasing K rs, Sdiff decreased (Figures 8 and 9). As a result, it is clear that K rs had a significant effect on the differential settlement but marginal on the total settlement. Therefore, the most effective way to reduce SR is to use a larger number of piles with longer lengths. To minimize Sdiff, in addition to increasing Lp/dp and Np, increasing K rs would be more effective. Figure 10 presents the Lp/dp versus GPR at different pile numbers. As expected, the GPR increased with increasing Lp/dp and Np. For example, the increase in GPR was 13.7, 36, and 58% with increasing Lp/dp from 10 to 30 for the number of piles 4, 9, and 16, respectively.

Figure 7 Effect of pile length on SR for different piled raft cases.
Figure 7

Effect of pile length on SR for different piled raft cases.

Figure 8 Effect of pile length on SR (Np = 9 and Sp/dp = 6).
Figure 8

Effect of pile length on SR (Np = 9 and Sp/dp = 6).

Figure 9 Effect of pile number on Sdiff (Lp/dp = 25 and Sp/dp = 6).
Figure 9

Effect of pile number on Sdiff (Lp/dp = 25 and Sp/dp = 6).

Figure 10 Effect of pile length on GPR at different pile numbers.
Figure 10

Effect of pile length on GPR at different pile numbers.

3.2 Effect of raft-soil relative stiffness (K rs)

Table 4 presents the loads carried by the center, edge, and corner piles for the case of the piled raft with Np = 9, Lp/dp = 20, and spaced 6dp. As shown, the corner pile carried the maximum load, followed by the edge pile, and finally the center pile. In addition, the piled raft with high K rs improved the distribution of load between the piles. Also, the total pile loads increased marginally with increasing K rs. Figure 11 shows the K rs versus GPR for different Np and Lp/dp. As shown, the effect of K rs on the GPR was marginal. Similar conclusions were obtained by Singh and Singh [29], Poulos [30] from numerical analysis, and El-Garhy et al. [7] from experimental analysis of piled rafts.

Table 4

Pile loads (N) for piled raft (Np = 9, Lp/dp = 20, and Sp/dp = 6)

K rs Center pile Edge pile Corner pile Total pile loads (Pp), N
0.08 88 119 123 1,056
0.70 112 127 133 1,152
10.43 120 131 135 1,184
Figure 11 Effect of raft-soil relative stiffness on the GPR.
Figure 11

Effect of raft-soil relative stiffness on the GPR.

3.3 Effect of the presence of the sand cushion

In a trial to improve the contact layer, simulations were carried out on piled rafts with the presence of a sand cushion beneath the raft with a thickness (Hc/dp) of 1, 2, 3, 4, and 5. Figures 12 and 13 show the effect of Hc/dp on SR and GPR for piled raft with Lp/dp = 25, Np = 9, and Sp = 6dp at different Rd values. Although the effect of placing a sand cushion on the shear strength of soft clay was neglected, the SR decreased with increasing Hc/dp at different relative densities (Figure 12). This decrease in the settlement occurred as a result of increasing the bearing capacity of the contact layer with increasing Hc/dp and Rd. The GPR decreased slowly as the Hc/dp and Rd increased (Figure 13) as a result of the load redistribution between raft and piles due to the presence of the sand cushion. For example, the GPR decreased by 8.1% with Hc/dp = 5 and Rd of 70% when compared to piled raft without the presence of the sand cushion. Therefore, to minimize SR and increase the load carried by the raft, using a sand cushion with reasonable thickness and a high Rd is a perfect solution.

Figure 12 Effect of the presence of a sand cushion on the SR.
Figure 12

Effect of the presence of a sand cushion on the SR.

Figure 13 Effect of the presence of a sand cushion on the GPR.
Figure 13

Effect of the presence of a sand cushion on the GPR.

3.4 Negative skin friction

It was found that the negative skin friction has a minor effect on pile geotechnical capacity. As the raft was subjected to vertical loads, it pushed the soil beneath the raft and the piles to settle together. So, there was no relative movement between the pile and soil beneath the raft. Polous [31] observed that it is prudent to design the piles to settle with the ground rather than attempt to restrain them from the settlement.

3.5 Scale effect and boundary conditions

According to Bezuijen [32], there is no scale effect of clay particle size in experimental tests. The clay particles are very small compared to the pile diameter. For the term of boundary conditions, Figure 14 shows the settlement shading of the piled raft with Np/dp = 9, Sp/dp = 6, and Lp/dp = 30 which represented the longest pile used in this study. It was observed that the selected boundaries effect could be neglected as the settlement shading showed only a minor effect.

Figure 14 Effect of boundary conditions.
Figure 14

Effect of boundary conditions.

4 Conclusions

The numerical study was performed to investigate the applicability and performance of piled rafts in soft clay. The effect of pile length (Lp), pile number (Np), raft-soil relative stiffness (K rs), and the presence of a sand cushion beneath the raft on the total settlement, differential settlement, and load sharing were studied. The following conclusions were given:

  • Piled rafts are effective and applicable in soft clay due to piles‘ efficiency in decreasing the total settlement and differential settlement.

  • With increasing pile number and pile length, total settlement and differential settlement decrease.

  • The increase in GPR is 13.7, 36, and 58% with increasing Lp/dp from 10 to 30 for the number of piles 4, 9, and 16, respectively.

  • The raft-soil relative stiffness has an important role in decreasing the differential settlement, whereas it has a marginal effect on the GPR.

  • The presence of a sand cushion beneath the raft decreases the total settlement efficiently and leads to a significant decrease in the total settlement.

  • The GPR decreases by 8.1% with Hc/dp = 5 and Rd of 70% when compared to piled raft without the presence of the sand cushion.

Acknowledgment

Alaaeldin Magdy wish to express his sincere gratitude to his brother Eng. Emad El-Din Ogail for his support and continuous encouragement.

  1. Funding information: The authors state no funding is involved.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Data availability statement: All data, and models used during the study appear in the submitted article.

References

[1] Lee J, Kim Y, Jeong S. Three-dimensional analysis of bearing behavior of piled raft on soft clay. Computers Geotech. 2010 Jan 1;37(1–2):103–14.10.1016/j.compgeo.2009.07.009Search in Google Scholar

[2] Reul O. Numerical study of the bearing behavior of piled rafts. Int J Geomech. 2004 Jun;4(2):59–68.10.1061/(ASCE)1532-3641(2004)4:2(59)Search in Google Scholar

[3] Karkush MO, Sabaa MR, Salman AD, Al-Rumaithi A. Prediction of bearing capacity of driven piles for Basrah governatore using SPT and MATLAB. J Mech Behav Mater. 2022 Jan 1;31(1):39–51.10.1515/jmbm-2022-0005Search in Google Scholar

[4] Cho J, Lee JH, Jeong S, Lee J. The settlement behavior of piled raft in clay soils. Ocean Eng. 2012 Oct 15;53:153–63.10.1016/j.oceaneng.2012.06.003Search in Google Scholar

[5] Sinha A, Hanna AM. 3D numerical model for piled raft foundation. Int J Geomech. 2017 Feb 1;17(2):04016055.10.1061/(ASCE)GM.1943-5622.0000674Search in Google Scholar

[6] Karkush MO, AbdulKareem MS, Dekhn H. Effect of deep remediation and improvement on bearing capacity and settlement of piled raft foundation subjected to static and cyclic vertical loading. Geomech Geoeng. 2021 Sep 15;1. 10.1080/17486025.2021.1975047.Search in Google Scholar

[7] El-Garhy B, Galil AA, Youssef AF, Raia MA. Behavior of raft on settlement reducing piles: experimental model study. J Rock Mech Geotech Eng. 2013 Oct 1;5(5):389–99.10.1016/j.jrmge.2013.07.005Search in Google Scholar

[8] Elwakil AZ, Azzam WR. Experimental and numerical study of piled raft system. Alex Eng J. 2016 Mar 1;55(1):547–60.10.1016/j.aej.2015.10.001Search in Google Scholar

[9] Mali S, Singh B. Behavior of large piled-raft foundation on clay soil. Ocean Eng. 2018 Feb 1;149:205–16.10.1016/j.oceaneng.2017.12.029Search in Google Scholar

[10] Thoidingjam D, Devi KR. Behavior of pile raft foundation in organic clay. Indian J Sci Technol. 2017 Aug 7;10(31):1–4.10.17485/ijst/2017/v10i31/113867Search in Google Scholar

[11] Karkush MO, Aljorany AN. Analytical and numerical analysis of piled-raft foundation of storage tank. In: Latha Gali M, Raghuveer Rao, editors. Construction in Geotechnical Engineering. Singapore: Springer; 2020. p. 373–84.10.1007/978-981-15-6090-3_26Search in Google Scholar

[12] Davids A, Wongso J, Popovic D, McFarlane A. A postcard from Dubai design and construction of some of the tallest buildings in the world. In Proceedings of the CTBUH 8th World Congress; 2008 Mar 3–5; Dubai, United Arab Emirates. CTBUH; 2008. p. 1–8.10.3850/9789628014194_0075Search in Google Scholar

[13] Leung YF, Soga K, Lehane BM, Klar A. Role of linear elasticity in pile group analysis and load test interpretation. J Geotech Geoenviron Eng. 2010 Dec;136(12):1686–94.10.1061/(ASCE)GT.1943-5606.0000392Search in Google Scholar

[14] Abdel-Fattah TT, Hemada AA. Use of creep piles to control settlement of raft foundation on soft clay—case study. In Proceedings of the 8th Alexandria International Conference on Structural and Geotechnical Engineering; 2014 Apr 14–16; Alexandria, Egypt. AICSGE; 2014. p. 89–109.Search in Google Scholar

[15] Hoang LT, Matsumoto T. Long-term behavior of piled raft foundation models supported by jacked-in piles on saturated clay. Soils Found. 2020 Feb 1;60(1):198–217.10.1016/j.sandf.2020.02.005Search in Google Scholar

[16] Hemsley JA, editor. Design applications of raft foundations. London: Thomas Telford; 2000.10.1680/daorf.27657Search in Google Scholar

[17] Sommer H. Piled raft foundation of a tall building in Frankfurt clay. In Proceedings of the 11th International Conference on Soil Mechanics and Foundation Engineering; 1985 Aug 12-16; San Francisco, USA. Milton Park: Routledge; 1985. p. 2253–7.Search in Google Scholar

[18] Sinha J. Piled raft foundations subjected to swelling and shrinking soils [dissertation]. Sydney: University of Sydney; 1997.Search in Google Scholar

[19] Abdelrahman GE, Elragi AF. Behavior improvement of footings on soft clay utilizing geofoam. In Proceedings of the 10th Arab Structural Engineering Conference. 2006;13:15.Search in Google Scholar

[20] Ilyas T, Leung CF, Chow YK, Budi SS. Centrifuge model study of laterally loaded pile groups in clay. J Geotech Geoenviron Eng. 2004 Mar;130(3):274–83.10.1061/(ASCE)1090-0241(2004)130:3(274)Search in Google Scholar

[21] Prandtl L. Uber Die Eindringungsfestigkeit (Harte) Plastischer Baustoffe Und Die Festigkeit Von Schneiden. Zamm –  J Appl Math Mech/Z Angew Math Und Mech. 1921;1(1):15–20.10.1002/zamm.19210010102Search in Google Scholar

[22] Yılmaz B. An analytical and experimental study on piled raft foundations [dissertation]. Ankara: Middle East Technical University; 2010.Search in Google Scholar

[23] Duncan JM, Chang CY. Nonlinear analysis of stress and strain in soils. J Soil Mech Found Div. 1970 Sep;96(5):1629–53.10.1061/JSFEAQ.0001458Search in Google Scholar

[24] Baguelin F, Frank R. Theoretical studies of piles using the finite element method. In Numerical methods in offshore piling. London: Thomas Telford Publishing; 1980. p. 83–91.Search in Google Scholar

[25] Taghavi Ghalesari A, Barari A, Fardad Amini P, Ibsen LB. Development of optimum design from static response of pile–raft interaction. J Mar Sci Technol. 2015 Jun;20(2):331–43.10.1007/s00773-014-0286-xSearch in Google Scholar

[26] Schanz T, Vermeer PA. Angles of friction and dilatancy of sand. Geotechnique. 1996 Mar;46(1):145–51.10.1680/geot.1996.46.1.145Search in Google Scholar

[27] Dutta TT, Saride S. Effect of confining pressure, relative density and shear strain on the Poisson’s ratio of clean sand. In Proceedings of the 50th Indian Geotechnical Conference. 2015 Dec 17-19; Pune, India. IGC; 2015. p. 17–9.Search in Google Scholar

[28] Brown PT. Strip footings with concentrated loads on deep elastic foundations. Research Report No. R 225, School of Civil Engineering. Australia: University of Sydney; 1973.Search in Google Scholar

[29] Singh B, Singh NT. Influence of piles on load-settlement behaviour of raft foundation. Int J Eng Sci Technol. 2011 Dec;3(12):8385–94.Search in Google Scholar

[30] Poulos HG. Piled raft foundations: design and applications. Geotechnique. 2001 Mar;51(2):95–113.10.1680/geot.2001.51.2.95Search in Google Scholar

[31] Poulos HG. A practical design approach for piles with negative friction. Proc Inst Civ Eng-Geotechn Eng. 2008 Feb;161(1):19–27.10.1680/geng.2008.161.1.19Search in Google Scholar

[32] Bezuijen A. Similitude in soil-structure and soil-soil interaction. The 3rd European Conference on Physical Modelling in Geotechnics; 2016 Jun 1–3; Nantes, France. ISSMGE; 2016. p. 43–8.Search in Google Scholar
Received: 2022-04-13
Revised: 2022-04-23
Accepted: 2022-05-06
Published Online: 2022-07-11

© 2022 Mostafa Elsawwaf et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Research Articles
  2. Calcium carbonate nanoparticles of quail’s egg shells: Synthesis and characterizations
  3. Effect of welding consumables on shielded metal arc welded ultra high hard armour steel joints
  4. Stress-strain characteristics and service life of conventional and asphaltic underlayment track under heavy load Babaranjang trains traffic
  5. Corrigendum to: Statistical mechanics of cell decision-making: the cell migration force distribution
  6. Prediction of bearing capacity of driven piles for Basrah governatore using SPT and MATLAB
  7. Investigation on microstructural features and tensile shear fracture properties of resistance spot welded advanced high strength dual phase steel sheets in lap joint configuration for automotive frame applications
  8. Experimental and numerical investigation of drop weight impact of aramid and UHMWPE reinforced epoxy
  9. An experimental study and finite element analysis of the parametric of circular honeycomb core
  10. The study of the particle size effect on the physical properties of TiO2/cellulose acetate composite films
  11. Hybrid material performance assessment for rocket propulsion
  12. Design of ER damper for recoil length minimization: A case study on gun recoil system
  13. Forecasting technical performance and cost estimation of designed rim wheels based on variations of geometrical parameters
  14. Enhancing the machinability of SKD61 die steel in power-mixed EDM process with TGRA-based multi criteria decision making
  15. Effect of boron carbide reinforcement on properties of stainless-steel metal matrix composite for nuclear applications
  16. Energy absorption behaviors of designed metallic square tubes under axial loading: Experiment-based benchmarking and finite element calculation
  17. Synthesis and study of magnesium complexes derived from polyacrylate and polyvinyl alcohol and their applications as superabsorbent polymers
  18. Artificial neural network for predicting the mechanical performance of additive manufacturing thermoset carbon fiber composite materials
  19. Shock and impact reliability of electronic assemblies with perimeter vs full array layouts: A numerical comparative study
  20. Influences of pre-bending load and corrosion degree of reinforcement on the loading capacity of concrete beams
  21. Assessment of ballistic impact damage on aluminum and magnesium alloys against high velocity bullets by dynamic FE simulations
  22. On the applicability of Cu–17Zn–7Al–0.3Ni shape memory alloy particles as reinforcement in aluminium-based composites: Structural and mechanical behaviour considerations
  23. Mechanical properties of laminated bamboo composite as a sustainable green material for fishing vessel: Correlation of layer configuration in various mechanical tests
  24. Singularities at interface corners of piezoelectric-brass unimorphs
  25. Evaluation of the wettability of prepared anti-wetting nanocoating on different construction surfaces
  26. Review Article
  27. An overview of cold spray coating in additive manufacturing, component repairing and other engineering applications
  28. Special Issue: Sustainability and Development in Civil Engineering - Part I
  29. Risk assessment process for the Iraqi petroleum sector
  30. Evaluation of a fire safety risk prediction model for an existing building
  31. The slenderness ratio effect on the response of closed-end pipe piles in liquefied and non-liquefied soil layers under coupled static-seismic loading
  32. Experimental and numerical study of the bulb's location effect on the behavior of under-reamed pile in expansive soil
  33. Procurement challenges analysis of Iraqi construction projects
  34. Deformability of non-prismatic prestressed concrete beams with multiple openings of different configurations
  35. Response of composite steel-concrete cellular beams of different concrete deck types under harmonic loads
  36. The effect of using different fibres on the impact-resistance of slurry infiltrated fibrous concrete (SIFCON)
  37. Effect of microbial-induced calcite precipitation (MICP) on the strength of soil contaminated with lead nitrate
  38. The effect of using polyolefin fiber on some properties of slurry-infiltrated fibrous concrete
  39. Typical strength of asphalt mixtures compacted by gyratory compactor
  40. Modeling and simulation sedimentation process using finite difference method
  41. Residual strength and strengthening capacity of reinforced concrete columns subjected to fire exposure by numerical analysis
  42. Effect of magnetization of saline irrigation water of Almasab Alam on some physical properties of soil
  43. Behavior of reactive powder concrete containing recycled glass powder reinforced by steel fiber
  44. Reducing settlement of soft clay using different grouting materials
  45. Sustainability in the design of liquefied petroleum gas systems used in buildings
  46. Utilization of serial tendering to reduce the value project
  47. Time and finance optimization model for multiple construction projects using genetic algorithm
  48. Identification of the main causes of risks in engineering procurement construction projects
  49. Identifying the selection criteria of design consultant for Iraqi construction projects
  50. Calibration and analysis of the potable water network in the Al-Yarmouk region employing WaterGEMS and GIS
  51. Enhancing gypseous soil behavior using casein from milk wastes
  52. Structural behavior of tree-like steel columns subjected to combined axial and lateral loads
  53. Prospect of using geotextile reinforcement within flexible pavement layers to reduce the effects of rutting in the middle and southern parts of Iraq
  54. Ultimate bearing capacity of eccentrically loaded square footing over geogrid-reinforced cohesive soil
  55. Influence of water-absorbent polymer balls on the structural performance of reinforced concrete beam: An experimental investigation
  56. A spherical fuzzy AHP model for contractor assessment during project life cycle
  57. Performance of reinforced concrete non-prismatic beams having multiple openings configurations
  58. Finite element analysis of the soil and foundations of the Al-Kufa Mosque
  59. Flexural behavior of concrete beams with horizontal and vertical openings reinforced by glass-fiber-reinforced polymer (GFRP) bars
  60. Studying the effect of shear stud distribution on the behavior of steel–reactive powder concrete composite beams using ABAQUS software
  61. The behavior of piled rafts in soft clay: Numerical investigation
  62. The impact of evaluation and qualification criteria on Iraqi electromechanical power plants in construction contracts
  63. Performance of concrete thrust block at several burial conditions under the influence of thrust forces generated in the water distribution networks
  64. Geotechnical characterization of sustainable geopolymer improved soil
  65. Effect of the covariance matrix type on the CPT based soil stratification utilizing the Gaussian mixture model
  66. Impact of eccentricity and depth-to-breadth ratio on the behavior of skirt foundation rested on dry gypseous soil
  67. Concrete strength development by using magnetized water in normal and self-compacted concrete
  68. The effect of dosage nanosilica and the particle size of porcelanite aggregate concrete on mechanical and microstructure properties
  69. Comparison of time extension provisions between the Joint Contracts Tribunal and Iraqi Standard Bidding Document
  70. Numerical modeling of single closed and open-ended pipe pile embedded in dry soil layers under coupled static and dynamic loadings
  71. Mechanical properties of sustainable reactive powder concrete made with low cement content and high amount of fly ash and silica fume
  72. Deformation of unsaturated collapsible soils under suction control
  73. Mitigation of collapse characteristics of gypseous soils by activated carbon, sodium metasilicate, and cement dust: An experimental study
  74. Behavior of group piles under combined loadings after improvement of liquefiable soil with nanomaterials
  75. Using papyrus fiber ash as a sustainable filler modifier in preparing low moisture sensitivity HMA mixtures
  76. Study of some properties of colored geopolymer concrete consisting of slag
  77. GIS implementation and statistical analysis for significant characteristics of Kirkuk soil
  78. Improving the flexural behavior of RC beams strengthening by near-surface mounting
  79. The effect of materials and curing system on the behavior of self-compacting geopolymer concrete
  80. The temporal rhythm of scenes and the safety in educational space
  81. Numerical simulation to the effect of applying rationing system on the stability of the Earth canal: Birmana canal in Iraq as a case study
  82. Assessing the vibration response of foundation embedment in gypseous soil
  83. Analysis of concrete beams reinforced by GFRP bars with varying parameters
  84. One dimensional normal consolidation line equation
https://doi.org/10.1515/jmbm-2022-0050
Keywords for this article
piled rafts; load sharing ratio; raft-soil relative stiffness; soft clay; sand cushion; numerical modeling
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. Calcium carbonate nanoparticles of quail’s egg shells: Synthesis and characterizations
  3. Effect of welding consumables on shielded metal arc welded ultra high hard armour steel joints
  4. Stress-strain characteristics and service life of conventional and asphaltic underlayment track under heavy load Babaranjang trains traffic
  5. Corrigendum to: Statistical mechanics of cell decision-making: the cell migration force distribution
  6. Prediction of bearing capacity of driven piles for Basrah governatore using SPT and MATLAB
  7. Investigation on microstructural features and tensile shear fracture properties of resistance spot welded advanced high strength dual phase steel sheets in lap joint configuration for automotive frame applications
  8. Experimental and numerical investigation of drop weight impact of aramid and UHMWPE reinforced epoxy
  9. An experimental study and finite element analysis of the parametric of circular honeycomb core
  10. The study of the particle size effect on the physical properties of TiO2/cellulose acetate composite films
  11. Hybrid material performance assessment for rocket propulsion
  12. Design of ER damper for recoil length minimization: A case study on gun recoil system
  13. Forecasting technical performance and cost estimation of designed rim wheels based on variations of geometrical parameters
  14. Enhancing the machinability of SKD61 die steel in power-mixed EDM process with TGRA-based multi criteria decision making
  15. Effect of boron carbide reinforcement on properties of stainless-steel metal matrix composite for nuclear applications
  16. Energy absorption behaviors of designed metallic square tubes under axial loading: Experiment-based benchmarking and finite element calculation
  17. Synthesis and study of magnesium complexes derived from polyacrylate and polyvinyl alcohol and their applications as superabsorbent polymers
  18. Artificial neural network for predicting the mechanical performance of additive manufacturing thermoset carbon fiber composite materials
  19. Shock and impact reliability of electronic assemblies with perimeter vs full array layouts: A numerical comparative study
  20. Influences of pre-bending load and corrosion degree of reinforcement on the loading capacity of concrete beams
  21. Assessment of ballistic impact damage on aluminum and magnesium alloys against high velocity bullets by dynamic FE simulations
  22. On the applicability of Cu–17Zn–7Al–0.3Ni shape memory alloy particles as reinforcement in aluminium-based composites: Structural and mechanical behaviour considerations
  23. Mechanical properties of laminated bamboo composite as a sustainable green material for fishing vessel: Correlation of layer configuration in various mechanical tests
  24. Singularities at interface corners of piezoelectric-brass unimorphs
  25. Evaluation of the wettability of prepared anti-wetting nanocoating on different construction surfaces
  26. Review Article
  27. An overview of cold spray coating in additive manufacturing, component repairing and other engineering applications
  28. Special Issue: Sustainability and Development in Civil Engineering - Part I
  29. Risk assessment process for the Iraqi petroleum sector
  30. Evaluation of a fire safety risk prediction model for an existing building
  31. The slenderness ratio effect on the response of closed-end pipe piles in liquefied and non-liquefied soil layers under coupled static-seismic loading
  32. Experimental and numerical study of the bulb's location effect on the behavior of under-reamed pile in expansive soil
  33. Procurement challenges analysis of Iraqi construction projects
  34. Deformability of non-prismatic prestressed concrete beams with multiple openings of different configurations
  35. Response of composite steel-concrete cellular beams of different concrete deck types under harmonic loads
  36. The effect of using different fibres on the impact-resistance of slurry infiltrated fibrous concrete (SIFCON)
  37. Effect of microbial-induced calcite precipitation (MICP) on the strength of soil contaminated with lead nitrate
  38. The effect of using polyolefin fiber on some properties of slurry-infiltrated fibrous concrete
  39. Typical strength of asphalt mixtures compacted by gyratory compactor
  40. Modeling and simulation sedimentation process using finite difference method
  41. Residual strength and strengthening capacity of reinforced concrete columns subjected to fire exposure by numerical analysis
  42. Effect of magnetization of saline irrigation water of Almasab Alam on some physical properties of soil
  43. Behavior of reactive powder concrete containing recycled glass powder reinforced by steel fiber
  44. Reducing settlement of soft clay using different grouting materials
  45. Sustainability in the design of liquefied petroleum gas systems used in buildings
  46. Utilization of serial tendering to reduce the value project
  47. Time and finance optimization model for multiple construction projects using genetic algorithm
  48. Identification of the main causes of risks in engineering procurement construction projects
  49. Identifying the selection criteria of design consultant for Iraqi construction projects
  50. Calibration and analysis of the potable water network in the Al-Yarmouk region employing WaterGEMS and GIS
  51. Enhancing gypseous soil behavior using casein from milk wastes
  52. Structural behavior of tree-like steel columns subjected to combined axial and lateral loads
  53. Prospect of using geotextile reinforcement within flexible pavement layers to reduce the effects of rutting in the middle and southern parts of Iraq
  54. Ultimate bearing capacity of eccentrically loaded square footing over geogrid-reinforced cohesive soil
  55. Influence of water-absorbent polymer balls on the structural performance of reinforced concrete beam: An experimental investigation
  56. A spherical fuzzy AHP model for contractor assessment during project life cycle
  57. Performance of reinforced concrete non-prismatic beams having multiple openings configurations
  58. Finite element analysis of the soil and foundations of the Al-Kufa Mosque
  59. Flexural behavior of concrete beams with horizontal and vertical openings reinforced by glass-fiber-reinforced polymer (GFRP) bars
  60. Studying the effect of shear stud distribution on the behavior of steel–reactive powder concrete composite beams using ABAQUS software
  61. The behavior of piled rafts in soft clay: Numerical investigation
  62. The impact of evaluation and qualification criteria on Iraqi electromechanical power plants in construction contracts
  63. Performance of concrete thrust block at several burial conditions under the influence of thrust forces generated in the water distribution networks
  64. Geotechnical characterization of sustainable geopolymer improved soil
  65. Effect of the covariance matrix type on the CPT based soil stratification utilizing the Gaussian mixture model
  66. Impact of eccentricity and depth-to-breadth ratio on the behavior of skirt foundation rested on dry gypseous soil
  67. Concrete strength development by using magnetized water in normal and self-compacted concrete
  68. The effect of dosage nanosilica and the particle size of porcelanite aggregate concrete on mechanical and microstructure properties
  69. Comparison of time extension provisions between the Joint Contracts Tribunal and Iraqi Standard Bidding Document
  70. Numerical modeling of single closed and open-ended pipe pile embedded in dry soil layers under coupled static and dynamic loadings
  71. Mechanical properties of sustainable reactive powder concrete made with low cement content and high amount of fly ash and silica fume
  72. Deformation of unsaturated collapsible soils under suction control
  73. Mitigation of collapse characteristics of gypseous soils by activated carbon, sodium metasilicate, and cement dust: An experimental study
  74. Behavior of group piles under combined loadings after improvement of liquefiable soil with nanomaterials
  75. Using papyrus fiber ash as a sustainable filler modifier in preparing low moisture sensitivity HMA mixtures
  76. Study of some properties of colored geopolymer concrete consisting of slag
  77. GIS implementation and statistical analysis for significant characteristics of Kirkuk soil
  78. Improving the flexural behavior of RC beams strengthening by near-surface mounting
  79. The effect of materials and curing system on the behavior of self-compacting geopolymer concrete
  80. The temporal rhythm of scenes and the safety in educational space
  81. Numerical simulation to the effect of applying rationing system on the stability of the Earth canal: Birmana canal in Iraq as a case study
  82. Assessing the vibration response of foundation embedment in gypseous soil
  83. Analysis of concrete beams reinforced by GFRP bars with varying parameters
  84. One dimensional normal consolidation line equation
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 1.10.2025 from https://www.degruyterbrill.com/document/doi/10.1515/jmbm-2022-0050/html?lang=en
Scroll to top button