Load–Settlement Response and Bearing Capacity of a Surface Footing Located Over a Conduit Buried Within a Soil Slope
This article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYPublication: International Journal of Geomechanics
Volume 20, Issue 10
Abstract
Engineers often face challenges when designing foundations that are located over buried structures. This paper presents a laboratory model test investigation of the load–settlement response and the bearing capacity of a surface footing located over a conduit, buried within a soil slope. An attempt is made to explain the effect of the crest distance of the footing, burial depth, and diameter of the conduit on the load-carrying ability of the footing based on its failure mechanism. The test results show that the burial depth of the conduit is the most important parameter that affects the settlement and bearing capacity of the surface footing. To avoid any detrimental effect on the load-carrying ability of the footing, the depth of the crown of the buried conduit needs to be at least three times the width of the footing. The graphical illustrations and the developed correlations, presented in this paper, can be used by practicing engineers to ensure the stability of the footing.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was funded by The Higher Education Commission, Government of the Islamic Republic of Pakistan (Project ID: G1003978). The authors also acknowledge the assistance provided by Muhammad Aamir in conducting the regression and sensitivity analysis.
Notation
The following symbols are used in this paper:
- Bc
- outer diameter of the conduit (mm);
- Bc1
- outer diameter (80 mm) of conduit (mm);
- Bc2
- outer diameter (160 mm) conduit (mm);
- BCR
- bearing capacity ratio (dimensionless);
- Cc
- coefficient of curvature (dimensionless);
- Cu
- coefficient of uniformity (dimensionless);
- c
- cohesion (kPa);
- Dr
- relative density (%);
- D10
- effective grain size (mm);
- D30
- grain size corresponding to 30% finer by weight (mm);
- D60
- grain size corresponding to 60% finer by weight (mm);
- E
- Young's modulus of the conduit material (MPa);
- e
- Euler's number (dimensionless);
- e/B
- crest distance of the edge of the footing from the slope edge (dimensionless);
- emax
- maximum void ratio (dimensionless);
- emin
- minimum void ratio (dimensionless);
- Gs
- specific gravity of soil (dimensionless);
- i
- angle of the soil slope (degrees);
- q
- applied surface pressure (kPa);
- qu
- ultimate bearing capacity of the surface footing without the buried conduit (kPa);
- qu,pipe
- ultimate bearing capacity of the surface footing with the buried conduit (kPa);
- (R2)
- coefficient of determination (dimensionless);
- RCR
- relative contribution ratio (dimensionless);
- ril
- radius of the logarithmic spiral OP at pole angle θl (mm);
- ris
- radius of the logarithmic spiral OR at pole angle θs (mm);
- rol
- initial radius of the logarithmic spiral OP (mm);
- ros
- initial radius of the logarithmic spiral OR (mm);
- s/B
- settlement of the surface footing (%);
- Xl
- base dimension of the elastic wedge MNO on the level ground side (mm);
- Xs
- base dimension of the elastic wedge MNO on the slope side (mm);
- z/B
- depth of the crown of the buried conduit from the soil surface (dimensionless);
- γdmax
- maximum dry unit weight (kN/m3);
- γdmin
- minimum dry unit weight (kN/m3);
- θl
- pole angle of the logarithmic spiral on the level ground side (degrees);
- θs
- pole angle of the logarithmic spiral on the slope side (degrees);
- ν
- Poisson's ratio of the conduit material (dimensionless);
- ϕ
- friction angle (degrees);
- ωl
- internal angle of MNO on the level ground side (degrees); and
- ωs
- internal angle of MNO on the slope side (degrees).
References
ASTM. 2011. Standard practice for classification of soils for engineering purposes (unified soil classification system). ASTM D2487. West Conshohocken, PA: ASTM.
Bildik, S., and M. Laman. 2015. “Experimental investigation of the effects of pipe location on the bearing capacity.” Geomech. Eng. 8 (2): 221–235. https://doi.org/10.12989/gae.2015.8.2.221.
Bildik, S., and M. Laman. 2019. “Experimental investigation of soil-structure-pipe interaction.” KSCE J. Civ. Eng. 23 (9): 3753–3763. https://doi.org/10.1007/s12205-019-0134-y.
Bowles, L. E. 1996. Foundation analysis and design. New York: McGraw-Hill.
Budhu, M. 2012. “Design of shallow footings on heavily overconsolidated clays.” Can. Geotech. J. 49 (2): 184–196. https://doi.org/10.1139/t11-093.
Castelli, F., and V. Lentini. 2012. “Evaluation of the bearing capacity of footings on slopes.” Int. J. Phys. Modell. Geotech. 12 (3): 112–118. https://doi.org/10.1680/ijpmg.11.00015.
Castelli, F., and E. Motta. 2010. “Bearing capacity of strip footings near slopes.” Geotech. Geol. Eng. 28 (2): 187–198. https://doi.org/10.1007/s10706-009-9277-9.
Chapman, D. N., P. R. Fleming, C. D. F. Rogers, and R. Talby. 2007. “The response of flexible pipes buried in sand to static surface stress.” Geomech. Geoeng. 2 (1): 17–28. https://doi.org/10.1080/17486020601150613.
Craig, R. F. 2004. Craig’s soil mechanics. New York: Taylor and Francis.
Dhar, A. S., I. D. Moore, and T. J. McGrath. 2004. “Two-dimensional analyses of thermoplastic culvert deformations and strains.” J. Geotech. Geoenviron. Eng. 130 (2): 199–208. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:2(199).
Faragher, E., P. R. Fleming, and C. D. F. Rogers. 2000. “Analysis of repeated-load field testing of buried plastic pipes.” J. Transp. Eng. 126 (3): 271–277. https://doi.org/10.1061/(ASCE)0733-947X(2000)126:3(271).
Foye, K. C., P. Basu, and M. Prezzi. 2008. “Immediate settlement of shallow foundations bearing on clay.” Int. J. Geomech. 8 (5): 300–310. https://doi.org/10.1061/(ASCE)1532-3641(2008)8:5(300).
Getzler, Z., M. Gellert, and R. Eitan. 1970. “Analysis of arching pressures in ideal elastic soil.” J. Soil Mech. Found. Div. 96 (4): 1357–1072.
Giroud, J. P., and V.-N. Tran. 1971. “Force portante d’une fondation sur une pente.” Ann. Inst. Tech. Bdtim. Trav. Publics 283: 129–157.
Graham, J., M. Andrews, and D. H. Shields. 1988. “Stress characteristics for shallow footings in cohesionless slopes.” Can. Geotech. J. 25 (2): 238–249. https://doi.org/10.1139/t88-028.
Graham, J., and J. G. Stuart. 1971. “Scale and boundary effects in foundation analysis.” J. Soil Mech. Found. Div. 97 (11): 1533–1548.
Gumbel, J. E. 1983. “Analysis and design of buried flexible pipes.” Ph.D. thesis, Dept. of Civil Engineering, Univ. of Surrey.
Halder, K., and D. Chakraborty. 2018. “Bearing capacity of strip footing placed on the reinforced soil slope.” Int. J. Geomech. 18 (11): 06018025. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001278.
Halder, K., D. Chakraborty, and S. K. Dash. 2019. “Bearing capacity of a strip footing situated on soil slope using a non-associated flow rule in lower bound limit analysis.” Int. J. Geotech. Eng. 13 (2): 103–111. https://doi.org/10.1080/19386362.2017.1325119.
Hovan, J. M. 1985. “Computation of bearing capacity and passive pressure coefficients in sand using stress-characteristics and critical state.” M.Sc. thesis, Faculty of Graduate Studies, Univ. of Manitoba.
Huang, C. C., and W. W. Kang. 2008. “The effects of a setback on the bearing capacity of a surface footing near a slope.” J. GeoEngineering 3 (1): 25–32.
Keskin, M. S., and M. Laman. 2013. “Model studies of bearing capacity of strip footing on sand slope.” KSCE J. Civ. Eng. 17 (4): 699–711. https://doi.org/10.1007/s12205-013-0406-x.
Kimura, T., O. Kusakabe, and K. Saitoh. 1985. “Geotechnical model tests of bearing capacity problems in a centrifuge.” Géotechnique 35 (1): 33–45. https://doi.org/10.1680/geot.1985.35.1.33.
Marston, A., and A. O. Anderson. 1913. The theory of loads on pipes in ditches, and tests of cement and clay drain tile and sewer pipe. Bulletin No. 31. Ames, IA: Engineering Experiment Station, Iowa State College of Agriculture and Mechanic Arts.
Mizuno, T., Y. Tokumitsu, and H. Kawakami. 1960. “On the bearing capacity of a slope of cohesionless soil.” Soils Found. 1 (2): 30–37. https://doi.org/10.3208/sandf1960.1.2_30.
Moser, A. P., and S. L. Folkman. 2001. Buried pipe design. New York: McGraw-Hill.
Peynircioglu, H. 1948. “Tests on bearing capacity of shallow foundations horizontal top surfaces of sand fills and the behaviour of soils under such foundations.” In Vol. 3 of Proc., 2nd Int. Conf. on Soil Mechanics and Foundation Engineering, 144–205, Rotterdam, Netherlands.
SA (Standards Australia). 2010. Australian standard for PVC-U pipes and fittings for stormwater and surface water applications. AS/NZS 1254. Sydney, Australia: Standards Australia.
SA (Standards Australia). 2014. Australian standard for the method of testing soils for engineering purposes, general requirements and list of methods. AS 1289.3.8.3. Sydney, Australia: Standards Australia.
SA (Standards Australia). 2017. Australian standard for PVC pipes and fittings for pressure applications. AS/NZS 1477. Sydney, Australia: Standards Australia.
Srivastava, A., C. R. Goyal, and A. Raghuvanshi. 2013. “Load settlement response of footing placed over buried flexible pipe through a model plate load test.” Int. J. Geomech. 13 (4): 477–481. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000228.
Talesnick, M. L., H. W. Xia, and I. D. Moore. 2011. “Earth pressure measurements on buried HDPE pipe.” Géotechnique 61 (9): 721–732. https://doi.org/10.1680/geot.8.P.048.
Terzaghi, K. 1943. Theoretical soil mechanics. New York: John Wiley and Sons.
Terzi, N. U. 2007. “Investigation of the effects of vertical and lateral loads on the stability of buried pipes.” Ph.D. thesis, Institute of Natural and Applied Science, Yildiz Technical Univ.
Tian, Y., and M. J. Cassidy. 2008. “Modeling of pipe–soil interaction and its application in numerical simulation.” Int. J. Geomech. 8 (4): 213–229. https://doi.org/10.1061/(ASCE)1532-3641(2008)8:4(213).
Veiskarami, M., J. Kumar, and F. Valikhah. 2014. “Effect of the flow rule on the bearing capacity of strip foundations on sand by the upper-bound limit analysis and slip lines.” Int. J. Geomech. 14 (3): 04014008. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000324.
Vesic, A. S. 1973. “Analysis of ultimate loads of shallow foundations.” J. Soil Mech. Found. Div 99 (1): 45–73.
Yang, S., B. Leshchinsky, K. Cui, F. Zhang, and Y. Gao. 2019. “Unified approach toward evaluating bearing capacity of shallow foundations near slopes.” J. Geotech. Geoenviron. Eng. 145 (12): 04019110. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002178.
Zhao, L. H., and F. Yang. 2013. “Construction of improved rigid blocks failure mechanism for ultimate bearing capacity calculation based on slip-line field theory.” J. Central South Univ. 20 (4): 1047–1057. https://doi.org/10.1007/s11771-013-1583-y.
Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 20 • Issue 10 • October 2020
Copyright
© 2020 American Society of Civil Engineers.
History
Received: Dec 19, 2019
Accepted: May 27, 2020
Published online: Jul 28, 2020
Published in print: Oct 1, 2020
Discussion open until: Dec 28, 2020
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.