|
|
|
| Experimental study on mechanical properties of red Pisha-sandstone under wet-dry cycles in Ordos |
| WU Shangyun, LI Xiaoli*, CHANG Ping, LI Mingyu,CHEN Suhang |
| College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China |
|
|
|
|
Abstract In order to analyse the mechanical properties of red Pisha-sandstone, the Pisha-sandstones with different particle sizes(<2 mm, 0.50-1.00 mm, 0.25-0.50 mm, and < 0.25 mm)in Jungar Banner, Ordos City, were tested with various dry-wet cycles(1, 3, 5, 7, 9), and the shrinkage deformation and strength characteristics of sandstone were obtained. Results show that the biggest shrinkage is reached after 3 dry-wet cycles for the Pisha-sandstone with < 2 mm particle size(original sandstone), for the sandstone with 0.50-1.00 mm particle size, however, its samples keep a slow contracting deposition. Interestingly, for the sandstone with < 0.25 mm particle size, the soil compactness achieves the maximum value at the 3rd cycle. On this basis, a direct shear device is applied to determine the shear strength of Pisha-sandstones. Under the same vertical load, the shear strength of the stone sample with <2 mm particle size increases with increasing number of cycles, but the maximum increment in the strength is exhibited in 1-3 cycles, and then the strength get large slightly. The shear strength of the sample with 0.50-1.00 mm particle size rises slowly and steadily with increasing number of cycles. The shear strength of the samples 0.25-0.50 mm and <0.25 mm particle sizes decreases a little initially then increases a bit and finally becomes saturated.. For the samples with <2 mm and 0.50-1.00 mm particle sizes, their internal friction angle increases with increasing number of cycles; for the samples with 0.25-0.50 mm and <0.25 mm particle sizes, however, the angle hardly changes with the number. For the samples with <2 mm and 0.50-1.00 mm particle sizes, the cohesion force increases firstly and keep flat basically; the samples with 0.25-~0.50 mm and <0.25 mm particle sizes, the force decreases initially then shows a small increase.
|
|
Received: 27 March 2016
|
|
|
|
| [1]李明玉, 李晓丽, 陈溯航,等. 冻融循环对鄂尔多斯砒砂岩重塑土样力学性能影响[J]. 排灌机械工程学报, 2016, 34(10):897-903. LI Mingyu, LI Xiaoli, CHEN Suhang,et al. Effects of freeze-thaw cycles on mechanical properties of Ordos remolded Pisha-sandstone soil [J]. Journal of drainage and irrigation machinery engineering,2016, 34(10): 897-903.(in Chinese)[2]陈溯航, 李晓丽, 张强,等. 鄂尔多斯红色砒砂岩冻融循环变形特性[J]. 中国水土保持科学, 2016, 14(4):34-41. CHEN Suhang,LI Xiaoli,ZHANG Qiang,et al. Deformation characteristics of red Pisha-sandstone during freezing-thawing cycles in Ordos[J]. Science of soil and water conservation,2016,14(4):34-41.(in Chinese)[3]倪万魁, 师华强. 冻融循环作用对黄土微结构和强度的影响[J]. 冰川冻土, 2014, 36(4):922-927. NI Wankui,SHI Huaqiang. Influence of freezing-thawing cycles on micro-structure and shear strength of loess[J].Journal of glaciology and geocryology,2014,36(4):922-927.(in Chinese)[4]方丽莉, 齐吉琳, 马巍. 冻融作用对土结构性的影响及其导致的强度变化[J]. 冰川冻土, 2012, 34(2):435-440. FANG Lili,QI Jilin,MA Wei. Freeze-thaw induced changes in soil structure and its relationship with variations in strength[J].Journal of glaciology and geocryology,2012,34(2):435-440.(in Chinese)[5]张芳枝,陈晓平.反复干湿循环对非饱和土的力学特性影响研究[J].岩土工程学报,2010,32(1):41-46. ZHANG Fangzhi,CHEN Xiaoping. Influence of repeated drying and wetting cycles on mechanical behaviors of unsaturated soil[J]. Chinese journal of geotechnical engineering,2010,32(1):41-46.(in Chinese)[6]尹宏磊,徐千军,李仲奎.抗剪强度随干湿循环变化对边坡安定性的影响[J].水利学报,2008,39(5):568-572,579. YIN Honglei, XU Qianjun, LI Zhongkui. Effect of shear strength variation on shakedown safety of slopes due to cyclic wetting-drying[J]. Journal of hydraulic engineering, 2008,39(5):568-572,579.(in Chinese)[7]曾召田, 吕海波, 赵艳林,等. 膨胀土干湿循环效应及其对边坡稳定性的影响[J]. 工程地质学报, 2012, 20(6):934-939. ZENG Zhaotian,LYU Haibo,ZHAO Yanlin,et al. Wetting-drying effect of expansive soils and its influence on slope stability[J].Journal of engineering geology,2012,20(6): 934-939.(in Chinese)[8]杨和平,张锐,郑健龙.有荷条件下膨胀土的干湿循环胀缩变形及强度变化规律[J].岩土工程学报,2006,28(11):1936-1941. YANG Heping,ZHANG Rui,,ZHENG JianLong. Variation of deformation and strength of expansive soil during cyclic wetting and drying under loading condition[J].Chinese journal of geotechnical engineering,2006,28(11):1936-1941.(in Chinese)[9]赵艳林,曾召田,吕海波.干湿循环对膨胀土变形指标的影响[J].桂林工学院学报,2009,29(4):470-473. ZHAO Yanlin,ZENG Zhaotian,LYU Haibo. Wetting-drying cycle influence on expansive soil deformation[J].Journal of Guilin University of Technology,2009,29(4): 470-473.(in Chinese)[10]ALHOMOUD A S, BASMA A A, MALKAWI A I H, et al. Cyclic swelling behavior of clays[J]. Journal of geotechnical engineering, 1995, 121(7):562-565.[11]刘华强,殷宗泽.裂缝对膨胀土抗剪强度指标影响的试验研究[J].岩土力学,2010,31(3): 727-731. LIU Huaqiang,YIN Zongze. Test study of influence of crack evolution on strength parameters of expansive soil [J]. Rock and soil mechanics,2010,31(3): 727-731.(in Chinese)[12]李晓丽, 于际伟, 刘李杰,等. 鄂尔多斯砒砂岩力学特性的试验研究[J]. 干旱区资源与环境, 2016, 30(5):118-123. LI Xiaoli,YU Jiwei,LIU Lijie,et al. The experimental research on mechanical properties of Pisha-sandstone of Ordos[J]. Journal of arid land resources and environment, 2016,30(5):118-123.(in Chinese)[13]杨和平,王兴正,肖杰. 干湿循环效应对南宁外环膨胀土抗剪强度的影响[J].岩土工程学报,2014, 36(5): 949-954. YANG Heping,WANG Xingzheng,XIAO Jie. Influence of wetting-drying cycles on strength characteristics of Nanning expansive soils[J].Chinese journal of geotechnical engineering,2014, 36(5):949-954.(in Chinese)[14]孙德安,黄丁俊. 干湿循环下南阳膨胀土的土水和变形特性[J].岩土力学,2015, 36(S1):115-119. SUN Dean,HUANG Dingjun. Soil-water and deformation characteristics of Nanyang expansive soil after wetting-drying cycles [J]. Rock and soil mechanics, 2015, 36(S1):115-119.(in Chinese)[15]ESTABRAGH A R, PARSAEI B, JAVADI A A. Laboratory investigation of the effect of cyclic wetting and drying on the behaviour of an expansive soil[J]. Soils & foundations, 2015, 55(2):304-314.[16]PINEDA J A, ROMERO E, GRACIA M D, et al. Shear strength degradation in claystones due to environmental effects[J]. Géotechnique, 2015, 64:1-9.[17]李晓丽,于际伟,刘李杰.鄂尔多斯砒砂岩土壤侵蚀与气候条件关系的研究[J].内蒙古农业大学学报(自然科学版),2014,35(3):105-109. LI Xiaoli,YU Jiwei,LIU Lijie.Study on relationship between Pisha-Standstone soil erosion and climatic conditions of Ordos[J].Journal of Inner Mongolia Agricultural University(natural science edition),2014,35(3):105-109.(in Chinese) |
|
|
|
