Multibench-Retained Excavations with Inclined–Vertical Framed Retaining Walls in Soft Soils: Observations and Numerical Investigation
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 150, Issue 5
Abstract
Strut-free retaining walls are an efficient and cost-effective technology for large-scale excavations, but their application at excavation depths of more than 10 m in soft soils has rarely been reported. An innovative multibench retaining system composed of an inclined–vertical framed retaining wall (IVFRW) and a cantilever wall with anchors was used in a 14.7-m-deep excavation in soft clay in Tianjin, China. To analyze the pile–soil interaction considering the influence of the second stepped excavation, indicators were monitored to provide comprehensive measured data. Field measurements included the lateral deflection and vertical displacement of the retaining wall, the ground water level variation, the ground settlement, and the axial force of the piles within the IVFRW. The measured results indicated that the wall displacements and the ground movements caused by the excavations were small in comparison to those of previous projects and empirical formulas. The influence of the second stepped excavation on the soil|structure interaction and its influence on the axial force of the IVFRW were analyzed. The optimal values of the first stepped excavation depth () for different site conditions were further investigated.
Practical Applications
This case study reports an application of multibench excavation with IVFRW in a 14.7-m excavation in soft soil area. Compared with propped excavations, the multibench excavation with IVFRW has comparable wall deflection while greatly reducing the material consumption and the construction duration. In addition, the amount of pile wall and pile wall length is greatly reduced in comparison to conventional multibench excavations in similar soil condition and excavation depths. This case history provides an economic and efficient strategy for professional engineers to integrate a similar solution in design. During the excavation process, the compressive stress accumulated on the inclined piles within IVFRW restricting the displacement of retaining structure. Due to the second stepped excavation affecting the development of the axial force of the inclined piles, the optimal excavation depth varies. In engineering design, a width of earth berm should be first determined according to the available workspace. An optimal stepped excavation depth can then be chosen based on this study to achieve the best deformation performance or a minimum material consumption.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
All data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
References
Abdi, A. S., and C.-Y. Ou. 2022. “A study of the failure mechanism of braced excavations using 3D finite-element analysis.” Int. J. Geomech. 22 (7): 04022084. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002385.
Benz, T. 2007. “Small-strain stiffness of soils and its numerical consequences.” Ph.D. thesis, Institute of Geotechnics, Univ. of Stuttgart.
Brinkgreve, R. B. J., S. Kumarswamy, and W. M. Swolfs. 2015. Plaxis 3D reference manual anniversary edition version 1. Plaxis, Delft. ISBN 978-90-76016-19-2. Delft, Netherlands: Plaxis Bv.
Bryson, L. S., and D. G. Zapata-Medina. 2012. “Method for estimating system stiffness for excavation support walls.” J. Geotech. Geoenviron. Eng. 138 (9): 1104–1115. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000683.
Clough, G. W., and T. D. O’Rourke. 1990. “Construction induced movements of in-situ walls.” In Geotechnical special publication: Design and performance of earth retaining structures (GSP 25), 439–470. Reston, VA: ASCE.
Cudny, M., and A. Truty. 2020. “Refinement of the Hardening Soil model within the small strain range.” Acta Geotech. 15 (8): 2031–2051. https://doi.org/10.1007/s11440-020-00945-5.
Daly, M. P., and W. Powrie. 2001. “Undrained analysis of earth berms as temporary supports for embedded retaining walls.” Proc. Inst. Civ. Eng. Geotech. Eng. 149 (4): 237–248. https://doi.org/10.1680/geng.2001.149.4.237.
Diao, Y., P. Zhu, Z. Jia, Z. Gang, Y. Du, D. Shang, and H. Zhou. 2021. “Stability analysis and safety factor prediction of excavation supported by inclined piles in clay.” Comput. Geotech. 140 (Dec): 104420. https://doi.org/10.1016/j.compgeo.2021.104420.
FPS (Federation of Piling Specialists) and ICE (Institution of Civil Engineers). 1999. The essential guide to the ICE’s specification for piling and embedded retaining walls. London: Thomas Telford Publishing.
Goh, A. T. C., F. Zhang, W. Zhang, and O. Y. S. Chew. 2017. “Assessment of strut forces for braced excavation in clays from numerical analysis and field measurements.” Comput. Geotech. 86 (Jun): 141–149. https://doi.org/10.1016/j.compgeo.2017.01.012.
Hashash, Y. M. A., and A. J. Whittle. 2002. “Mechanisms of load transfer and arching for braced excavations in clay.” J. Geotech. Geoenviron. Eng. 128 (3): 187–197. https://doi.org/10.1061/(ASCE)1090-0241(2002)128:3(187).
Hsieh, P. G., and C. Y. Ou. 1998. “Shape of ground surface settlement profiles caused by excavation.” Can. Geotech. J. 35 (6): 1004–1017. https://doi.org/10.1139/t98-056.
Hsieh, P. G., and C. Y. Ou. 2018. “Mechanism of buttress walls in restraining the wall deflection caused by deep excavation.” Tunnelling Underground Space Technol. 82 (Dec): 542–553. https://doi.org/10.1016/j.tust.2018.09.004.
ICE (Institution of Civil Engineers). 2016. ICE specification for piling and embedded retaining walls. London: ICE Publishing.
Ignat, R., S. Baker, S. Liedberg, and S. Larsson. 2016. “Behavior of braced excavation supported by panels of deep mixing columns.” Can. Geotech. J. 53 (10): 1671–1687. https://doi.org/10.1139/cgj-2016-0137.
Iwata, N., H. M. Shahin, F. Zhang, T. Nakai, M. Niinomi, and Y. D. S. Geraldni. 2008. “Excavation with stepped-twin retaining wall: Model tests and numerical simulations.” In Geotechnical aspects of underground construction in soft ground, 671–678. Boca Raton, FL: CRC Press.
Jeldes, I. A., E. C. Drumm, R. M. Bennett, and N. Zisi. 2015. “Piling framed concrete retaining wall: Design pressures and stability evaluation.” Pract. Period. Struct. Des. Constr. 20 (3): 04014041. https://doi.org/10.1061/(ASCE)SC.1943-5576.0000241.
Karthigeyan, S., V. V. G. S. T. Ramakrishna, and K. Rajagopal. 2007. “Numerical investigation of the effect of vertical load on the lateral response of piles.” J. Geotech. Geoenviron. Eng. 133 (5): 512–521. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:5(512).
Kim, G. H., U. K. Lee, U. Y. Park, J. Y. Kim, and K. I. Kang. 2005. “Modified braced wall system with pre-stressed wale for excavation in urban areas.” Build. Environ. 40 (12): 1689–1696. https://doi.org/10.1016/j.buildenv.2004.12.007.
Kung, G. T. C., C. Y. Ou, and C. H. Juang. 2009. “Modeling small-strain behavior of Taipei clays for finite element analysis of braced excavations.” Comput. Geotech. 36 (1–2): 304–319. https://doi.org/10.1016/j.compgeo.2008.01.007.
Kuwabara, F., and H. G. Poulos. 1989. “Downdrag forces in group of piles.” J. Geotech. Eng. 116 (6): 115806. https://doi.org/10.1061/(ASCE)0733-9410(1989)115:6(806).
Lam, S. Y., S. K. Haigh, and M. D. Bolton. 2014. “Understanding ground deformation mechanisms for multi-propped excavation in soft clay.” Soils Found. 54 (3): 296–312. https://doi.org/10.1016/j.sandf.2014.04.005.
Li, A. Z., and B. M. Lehane. 2010. “Embedded cantilever retaining walls in sand.” Géotechnique 60 (11): 813–823. https://doi.org/10.1680/geot.8.P.147.
Lim, A., C. Y. Ou, and P. G. Hsieh. 2018. “Investigation of the integrated retaining system to limit deformations induced by deep excavation.” Acta Geotech. 13 (4): 973–995. https://doi.org/10.1007/s11440-017-0613-6.
Lim, A., C. Y. Ou, and P. G. Hsieh. 2020. “A novel strut-free retaining wall system for deep excavation in soft clay: Numerical study.” Acta Geotech. 15 (6): 1557–1576. https://doi.org/10.1007/s11440-019-00851-5.
Liu, G. B., C. W. Ng, and Z. W. Wang. 2005. “Observed performance of a deep multistrutted excavation in Shanghai soft clays.” J. Geotech. Geoenviron. Eng. 131 (8): 1004–1013. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:8(1004).
Luo, Z., B. Hu, Y. Wang, and H. Di. 2018. “Effect of spatial variability of soft clays on geotechnical design of braced excavations: A case study of Formosa excavation.” Comput. Geotech. 103 (Nov): 242–253. https://doi.org/10.1016/j.compgeo.2018.07.020.
Meng, F. Y., R. P. Chen, H. N. Wu, S. W. Xie, and Y. Liu. 2020. “Observed behaviors of a long and deep excavation and collinear underlying tunnels in Shenzhen granite residual soil.” Tunnelling Underground Space Technol. 103 (Mar): 103504. https://doi.org/10.1016/j.tust.2020.103504.
Ng, C. W. W., Y. Hong, G. B. Liu, and T. Liu. 2012. “Ground deformations and soil–Structure interaction of a multi-propped excavation in Shanghai soft clays.” Géotechnique 62 (10): 907–921. https://doi.org/10.1680/geot.10.P.072.
Ou, C. Y., Y. L. Lin, and P. G. Hsieh. 2006. “Case record of an excavation with cross walls and buttress walls.” J. Geoeng. 1 (2): 79–87. https://doi.org/10.6310/jog.2006.1(2).4.
Ou, C.-Y., P.-G. Hsieh, and Y.-L. Lin. 2010. “Performance of excavations with cross walls.” J. Geotech. Geoenviron. Eng. 137 (1): 94–104. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000402.
Ou, C.-Y., J.-T. Liao, and H.-D. Lin. 1998. “Performance of diaphragm wall constructed using top-down method.” J. Geotech. Geoenviron. Eng. 124 (9): 798–808. https://doi.org/10.1061/(ASCE)1090-0241(1998)124:9(798).
Park, J.-S., Y.-S. Joo, and N.-K. Kim. 2009. “New earth retention system with prestressed wales in an urban excavation.” J. Geotech. Geoenviron. Eng. 135 (11): 1596–1604. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000148.
Peck, R. B. 1969. “Deep excavation and tunnelling in soft ground: State-of-the-art-report.” In Proc., 7th Int. Conf. of Soil Mechanics and Foundation Engineering, 225–281. London: International Society of Soil Mechanics and Geotechnical Engineering.
Powrie, W., and M. P. Daly. 2002. “Centrifuge model tests on embedded retaining walls supported by earth berms.” Géotechnique 52 (2): 89–106. https://doi.org/10.1680/geot.2002.52.2.89.
Seo, M., J. C. Im, C. Kim, and J. W. Yoo. 2016. “Study on the applicability of a retaining wall using batter piles in clay.” Can. Geotech. J. 53 (8): 1195–1212. https://doi.org/10.1139/cgj-2014-0264.
Sun, Y., S. Zhou, and Z. Luo. 2017. “Basal-heave analysis of pit-in-pit braced excavations in soft clays.” Comput. Geotech. 81 (Jan): 294–306. https://doi.org/10.1016/j.compgeo.2016.09.003.
Tan, Y., X. Li, Z. Kang, J. Liu, and Y. Zhu. 2014. “Zoned excavation of an oversized pit close to an existing metro line in stiff clay: Case study.” J. Perform. Constr. Facil. 29 (6): 04014158. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000652.
Tan, Y., and G. Lin. 2014. “Comprehensive load test on prestressed concrete piles in alluvial clays and marl in Savannah, Georgia.” J. Perform. Constr. Facil. 28 (1): 178–190. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000305.
Tan, Y., Y. Lu, and D. Wang. 2017a. “Deep excavation of the Gate of the Orient in Suzhou stiff clay: Composite earth-retaining systems and dewatering plans.” J. Geotech. Geoenviron. Eng. 144 (3): 05017009. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001837.
Tan, Y., Y. Lu, C. Xu, and D. Wang. 2018. “Investigation on performance of a large circular pit-in-pit excavation in clay-gravel-cobble mixed strata.” Tunnelling Underground Space Technol. 79 (May): 356–374. https://doi.org/10.1016/j.tust.2018.06.023.
Tan, Y., and D. Wang. 2013a. “Characteristics of a large-scale deep foundation pit excavated by the central-island technique in Shanghai soft clay. I: Bottom-up construction of the central cylindrical shaft.” J. Geotech. Geoenviron. Eng. 139 (11): 1875–1893. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000928.
Tan, Y., and D. Wang. 2013b. “Structural behaviors of large underground earth-retaining systems in Shanghai. I: Unpropped circular diaphragm wall.” J. Perform. Constr. Facil. 29 (2): 04014058. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000521.
Tan, Y., B. Wei, Y. Diao, and X. Zhou. 2013. “Spatial corner effects of long and narrow multipropped deep excavations in Shanghai soft clay.” J. Perform. Constr. Facil. 28 (4): 04014015. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000475.
Tan, Y., H. Zhu, F. Peng, K. Karlsrud, and B. Wei. 2017b. “Characterization of semi-top-down excavation for subway station in Shanghai soft ground.” Tunnelling Underground Space Technol. 68 (Sep): 244–261. https://doi.org/10.1016/j.tust.2017.05.028.
Wu, S.-H., J. Ching, and C.-Y. Ou. 2012. “Predicting wall displacements for excavations with cross walls in soft clay.” J. Geotech. Geoenviron. Eng. 139 (6): 914–927. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000826.
Yeh, T., C. Ou, and A. Lim. 2022. “A case study of strut-free excavation retaining system.” Acta Geotech. 17 (12): 5557–5571. https://doi.org/10.1007/s11440-022-01526-4.
Zhang, W., Z. Hou, A. T. Goh, and R. Zhang. 2019. “Estimation of strut forces for braced excavation in granular soils from numerical analysis and case histories.” Comput. Geotech. 106 (Feb): 286–295. https://doi.org/10.1016/j.compgeo.2018.11.006.
Zheng, G., Z. Guo, H. Zhou, D. Yu, E. Wang, X. He, Y. Tian, and Z. Liu. 2022a. “Parametric studies of wall displacement in excavations with inclined framed retaining walls.” Int. J. Geomech. 22 (9): 04022157. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002499.
Zheng, G., X. He, H. Zhou, Y. Diao, Z. Li, and X. Liu. 2022b. “Performance and mechanism of batter-vertical framed retaining wall for excavation in clay.” Tunnelling Underground Space Technol. 130 (8): 104767. https://doi.org/10.1016/j.tust.2022.104767.
Zheng, G., Q. H. Li, X. S. Cheng, D. Ha, J. C. Shi, X. R. Shi, and Y. W. Lei. 2022c. “Diaphragm wall deformation and ground settlement caused by dewatering before excavation in strata with leaky aquifers.” Géotechnique 74 (1): 1–11. https://doi.org/10.1680/jgeot.21.00146.
Zheng, G., and H. Liu. 2011. R. Examples of foundation pit support design in soft soil area. [In Chinese.] Beijing: China Architecture & Building Press.
Zheng, G., Z. P. Liu, H. Z. Zhou, X. P. He, and Z. Y. Guo. 2022d. “Behaviour of an outward inclined-vertical framed retaining wall of an excavation.” Acta Geotech. 17 (12): 5521–5532. https://doi.org/10.1007/s11440-022-01571-z.
Zheng, G., D. Nie, Y. Diao, J. Liu, and X. Cheng. 2017. “Numerical and experimental study of multibench retained excavations.” Geomech. Eng. 13 (5): 715–742. https://doi.org/10.12989/gae.2017.13.5.715.
Zheng, G., X. Yang, H. Zhou, Y. Du, J. Sun, and X. Yu. 2018. “A simplified prediction method for evaluating tunnel displacement induced by laterally adjacent excavations.” Comput. Geotech. 95 (Mar): 119–128. https://doi.org/10.1016/j.compgeo.2017.10.006.
Zhou, H. Z., G. Zheng, X. P. He, E. Y. Wang, Z. Y. Guo, D. Q. Nie, and S. K. Ma. 2020. “Numerical modelling of retaining structure displacements in multibench retained excavations.” Acta Geotech. 15 (9): 2691–2703. https://doi.org/10.1007/s11440-020-00947-3.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 150 • Issue 5 • May 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: May 19, 2023
Accepted: Dec 13, 2023
Published online: Feb 28, 2024
Published in print: May 1, 2024
Discussion open until: Jul 28, 2024
ASCE Technical Topics:
- Analysis (by type)
- Construction engineering
- Construction methods
- Continuum mechanics
- Displacement (mechanics)
- Engineering fundamentals
- Engineering mechanics
- Excavation
- Foundations
- Geomechanics
- Geotechnical engineering
- Numerical analysis
- Pile foundations
- Pile settlement
- Retaining structures
- Soft soils
- Soil analysis
- Soil dynamics
- Soil mechanics
- Soil properties
- Soil settlement
- Soils (by type)
- Solid mechanics
- Structural mechanics
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.
Cited by
- Gang Zheng, Wenbin Zhang, Haizuo Zhou, Davide Forcellini, Jihui Zhao, Tianqi Zhang, 3D Numerical Modeling of the Inertial and Kinematic Interactions of Inclined Pile Groups in Liquefiable Soils, International Journal of Geomechanics, 10.1061/IJGNAI.GMENG-9705, 24, 8, (2024).
- Xiaopei He, Xiaomin Liu, Zhaopeng Liu, Performance and Mechanism of Double-Row Capsule Grouting to Protect Tunnels Adjacent to Excavation, International Journal of Geomechanics, 10.1061/IJGNAI.GMENG-9465, 24, 9, (2024).