摘要(英) |
Abstract
Landslide is a typical natural disaster around the world. Factors such as slope material, intensity and duration of rainfall, earthquakes and loadings, infiltration and seepage conditions strongly influence the stability of slope because of the decrease in resistance forces or the increase of driving force. A lot of methods for increasing slope stability are already developed nowadays. This research using C-RHA columns for slope strengthening. C-RHA mortar was made of cement, sand and microsilica from fine rice husk ash (RHA). Replacement 10 % of the weight of cement by RHA would increase the strength of the column.
The effect of C-RHA columns on slope stability simulated by a series of centrifuge modeling tests which were conducted at the Experimental Center of Civil Engineering, Department of Civil Engineering, National Central University. The slope is prepared by moist tamping method at optimum water content about 12 % with a mixture material consist of 20 % of the fine content (kaolinite) and 80 % of quartz sand. The C-RHA columns were penetrated perpendicular to the slope surface. During the test, the acceleration was gradually increased until the slope failed. The process of the failure was recorded through cameras during centrifuge spinning. Cameras and laser displacement scanner record the failure process, slope deformation and ground surface change.
The decreasing spacing of C-RHA column increases the safety factor of the slope. The test results show that when the spacing between the C-RHA columns is reduced, the timing of the cracks at the top of the slope can be delayed, and the location of the cracks will be far away from the top of the slope, which will delay the timing of the slope failure. In this case delay means reaching higher g level. The first crack of the slope without column occurs at 40 g, the crack depth is about 0.33h, the second crack occurs at 45 g, and the damage occurs at the 50 g. When the spacing of the slope is 6.7d, 5d and 4d, the first crack of the slope occurs at 40 g, 45 g and 55 g, respectively, and the crack depth is 0.30h, 0.33h times and 0.56h. The second crack occurred at 43 g, 49 g, and 65 g, and fail at 48 g, 55 g, and 65 g. From the side view of the slope, the decreasing number of C-RHA column spacing will decrease the depletion mass of slope, which is the volume of displaced soil that overlies the failure surface but underlies the original ground surface. The depletions mass normalized by the volume of theoretical planar failure wedge with failure angle of θ=(β+?)/2 are 67.0 %, 64.5 %, 59.3 % and 48.6 %, respectively.
Keywords: C-RHA, Centrifuge modeling, Slope Stability |
參考文獻 |
References
[1] Abramson, Lee W., Lee, Thomas S., Sharma, Sunhill, Boyce, Glenn M., “Slope Stability and Stabilization Methods”, John Wiley & Sons, Inc., New York, New York. 1996
[2] Caspar Thrane Leth. "Improved Design Basis for Laterally Loaded Large Diameter Pile: Experimental Based Approach", River Publishers, 2014
[3] Chaulya, S.K. External Dumping of Overburden in Opencast Mine. Indian Jour. Engineers, v.22 (1 & 2), pp.65-73, 1992
[4] Duncan M. J. and Wright G. S. “Soil strength and Slope Stability”. John Wiley & Sons.INC, 2005
[5] H. X Research on construction technology for strengthening of accumulation body high slope of ancient landslide Sino-Hydro Engineering Bureau No. 4 Co., Ltd., Beijing, 2009
[6] G. E. Barnes. "Chapter 7 Shear Strength", Springer Nature, 1995
[7] Galandarzadeh, Abbas, Mehdi Ashtiani, and Ikuo Towhata. "Centrifuge modeling of shallow embedded foundations subjected to reverse fault rupture", Canadian Geotechnical Journal, 2015.
[8] "Landslide Science for a Safer Geo environment", Springer Nature, 2014
[9] Lee, C, H Chen, and W Hung. "The scaling effect of reinforcement strength for GREW in centrifuge modeling test", Physical Modelling in Geotechnics Proceedings of the Sixth International Conference on Physical Modelling in Geotechnics 6th ICPMG 06 Hong Kong, 2006.
[10] Luk, S.F.. "Heating performance of electrolytic heat-treatment in aqueous solution by pulse current", Journal of Materials Processing Tech., 1997
[11] Ling, Hoe I., Min-Hao Wu, Dov Leshchinsky, and Ben Leshchinsky. "Centrifuge Modeling of Slope Instability", Journal of Geotechnical and Geoenvironmental Engineering, 2009.
[12] Milne, F.D.. "Centrifuge modelling of hillslope debris flow initiation", Catena, 2012
[13] M. Rabie. "Comparison study between traditional and finite element methods for slopes under heavy rainfall", HBRC Journal, 2014
[14] K. Abdul-Hassan “Stability analysis of side slope by using stone column and tieback support”, International Journal of Scientific & Engineering Research, Volume 5, Issue 9, 2015
[15] J.P. Zhou Engineered slopes in China – approaches and case studies China Water Power Press, Beijing, 2008
[16] S. Vasantha Kumar. "Effect of deforestation on landslides in Nilgiris district — A case study", Journal of the Indian Society of Remote Sensing, 2008
[17] Shi-Jin Feng, Feng-Lei Du, H.X. Chen, Jian-Zhi Mao. "Centrifuge modeling of preloading consolidation and dynamic compaction in treating dredged soil", Engineering Geology, 2017
[18] Seyed Alireza Zareei, Farshad Ameri, Farzan Dorostkar, Mojtaba Ahmadi. "Rice husk ash as a partial replacement of cement in high strength concrete containing micro silica: Evaluating durability and mechanical properties", Case Studies in Construction Materials, 2017
[19] Poulos Design of reinforcing piles to increase slope stability Canadian Geotechnical Journal, 32 (5) , pp. 808-818, 1995
[20] Taylor, R.N., “Centrifuges in modelling: principles and scale effects,” Geotechnical centrifuge technology, pp.19-33, 1995.
[21] V. Ramasamy. "Compressive strength and durability properties of Rice Husk Ash concrete", KSCE Journal of Civil Engineering, 2012
[22] Wang Z, Sun B. Multi-anchoring point anti-sliding pile adapted to multilayer slide surface and deep sliding face. Chinese Patents, CN101067301, 2007
[23] Yaeger,S., ”Slope Stability and Methods of Increasing the Factor of Safety“,ECI 281a, Department of Civil and Environmental Engineering, University of California, Davis, 2002
[24] Yuzhen Yu. "Centrifuge modeling of a dry sandy slope response to earthquake loading", Bulletin of Earthquake Engineering, 2008
[25] Wen-Yi Hung, Chung-Jung Lee, Lin-Mao Hu. "Study of the effects of container boundary and slope on soil liquefaction by centrifuge modeling", Soil Dynamics and Earthquake Engineering, 2018
[26] Zhao, Yu Tong, Zhi-Yi Lu, Qing. "Slope stability analysis using slice-wise factor of safety. (Research Article) (Report)", Mathematical Problems in Engineering, Annual, 2014
[27] Z.Y. Chen, X.G. Wang, J. Yang, Z.J. Jia, Y.J. Wang Rock slope stability analysis: theory, methods and programs China Water Power Press, Beijing, 2005 |