Abstract：In light of that the periodical temperature changing leads to mechanical properties deterioration of rock bolts during the snowmelt period in spring，the relationship between bearing capacity of rock bolts and freeze-thaw cycles was studied. The freeze-thaw cycling experiments were conducted first for rock bolt specimens under different freeze-thaw cycles；and then the pull-out experiments were carried out. The displacement，stress and failure load of bolt，stress of rock，shear strength at the bolt-grout interface were investigated；the failure mode and main destruction factor under freeze-thaw conditions were studied with load transfer mechanism. It is shown that the elastic modulus and strength of mortar decreases along with the increase of freeze-thaw cycles；the mortar near the loading end splits ahead of time and accelerates load transferring to the inside of bolt；the internal stresses of bolt and bond increase. The ultimate bearing capacity of bolt decreases while the deformation of bolt increases under freeze-thaw conditions；the inflection point in load-displacement curve and horizontal segment in slipping curve of bolt will appear in advance along with the increase of freeze-thaw cycles.
[1] DELHOMME F，DEBICKI G，CHAIB Z. Experimental behavior of anchor bolts under pullout and relaxation tests[J]. Construction and Building Materials，2010，24(3)：266–274.
[2] DEB D，DAS K C. Modeling of fully grouted rock bolt based on enriched finite element method[J]. International Journal of Rock Mechanics and Mining Sciences，2011，48(2)：283–293.
[3] 许宏发，王 武，江 淼，等. 灌浆岩石锚杆拉拔变形和刚度的理论解析[J]. 岩土工程学报，2011，33(10)：1 511–1 516.(XU Hongfa，WANG Wu，JIANG Miao，et al. Theoretical analysis of pullout deformation and stiffness of grouted rock bolts[J]. Chinese Journal of Geotechnical Engineering，2011，33(10)：1 511–1 516.(in Chinese))
[4] 张 伟，刘泉声. 节理岩体锚杆的综合变形分析[J]. 岩土力学，2012，33(4)：1 067–1 074.(ZHANG Wei，LIU Quansheng. Synthetical deformation analysis of anchor bolt in jointed rock mass[J]. Rock and Soil Mechanics，2012，33(4)：1 067–1 074.(in Chinese))
[5] ELIGEHAUSEN R，MALLEE R，SILVA J F. Anchorage in concrete construction[M]. Berlin：Ernst und Sohn Verlag für Architektur und technische Wissenschaften GmbH and Co.，2006：259–264.
[6] 安玉科，佴 磊. 冻融循环作用下节理岩体锚固性能退化机制和模式[J]. 吉林大学学报：地球科学版，2012，42(2)：462–467.(AN Yuke，NAI Lei. Mechanism and style of anchorage degradation in jointed rock mass under cycle of freezing and thawing[J]. Journal of Jilin University：Earth Science，2012，42(2)：462–467.(in Chinese))
[7] 项 伟，刘 珣. 冻融循环条件下岩石–喷射混凝土组合试样的力学特性试验研究[J]. 岩石力学与工程学报，2010，29(12)：2 510–2 521. (XIANG Wei，LIU Xun. Experimental study of mechanical properties of combined specimen with rock and shotcrete under freezing-thawing cycles[J]. Chinese Journal of Rock Mechanics and Engineering， 2010，29(12)：2 510–2 521.(in Chinese))
[8] 项 伟，王 琰，贾海梁. 冻融循环条件下岩体–喷层结构模型试验研究[J]. 岩石力学与工程学报，2011，30(9)：1 819–1 826.(XIANG Wei，WANG Yan，JIA Hailiang. Model test study of rock-shotcrete layer structure under freezing-thawing cycles[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(9)：1 819–1 826.(in Chinese))
[9] 孙 奇. GFRP锚杆冻融循环与长期荷载作用力学性能试验研究[硕士学位论文][D]. 长沙：中南大学，2012.(SUN Qi. Experimental study on mechanical properties of GFRP bolt after freezing-thawing cycles and long-term load effects[M. S. Thesis][D]. Changsha：Central South University，2012.(in Chinese))
[10] KILIC A，YASAR E，ATIS C D. Effect of bar shape on the pull-out capacity of fully-grouted rock bolts[J]. Tunnelling and Underground Space Technology，2003，18(1)：1–6.
[11] 朱焕春，荣 冠，肖 明，等. 张拉荷载下全长黏结锚杆工作机制试验研究[J]. 岩石力学与工程学报，2002，21(3)：379–384.(ZHU Huanchun，RONG Guan，XIAO Ming，et al. Testing study on working mechanism of full grouting bolt under tensile load[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(3)：379–384.(in Chinese))
[12] 朱焕春，吴海滨，赵海斌. 反复张拉荷载作用下锚杆工作机制试验研究[J]. 岩土工程学报，1999，21(6)：662–665.(ZHU Huanchun，WU Haibin，ZHAO Haibin. Experimental study on bolting mechanism under cyclic tensile load[J]. Chinese Journal of Geotechnical Engineering，1999，21(6)：662–665.(in Chinese))
[13] BENMOKRANE B，CHENNOUF A，MITRI H S. Laboratory evaluation of cement-based grouts and grouted rock anchors[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1995，32(7)：633–642.
[14] 刘 波，李东阳，段艳芳，等. 锚杆–砂浆界面黏结滑移关系的试验研究与破坏过程解析[J]. 岩石力学与工程学报，2011，30(增1)：2 790–2 797.(LIU Bo，LI Dongyang，DUAN Yanfang，et al. Experimental study of bond-slip relationship between bolt and Mortar and theoretical solution to failure process[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(Supp.1)：2 790–2 797.(in Chinese))
[15] 曾宪明，林大路，李世民，等. 锚固类结构杆体临界锚固长度问题综合研究[J]. 岩石力学与工程学报，2009，28(增2)：3 609–3 625. (ZENG Xianming，LIN Dalu，LI Shimin，et al. Comprehensive research of critical anchorage length problem of rod of anchorage structure[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(Supp.2)：3 609–3 625.(in Chinese))
[16] 易 成，朱红光，王洪涛，等. 轴压下两体力学模型的转化条件及影响因素分析[J]. 岩土力学，2011，32(5)：1 297–1 302.(YI Cheng， ZHU Hongguang，WANG Hongtao，et al. Analysis of transformation conditions and influence factors of uni-body and bi-body models under axial compression[J]. Rock and Soil Mechanics，2011，32(5)：1 297–1 302.(in Chinese))
[17] 祝金鹏. 冻融循环后混凝土力学性能的试验研究[硕士学位论文][D]. 山东：山东大学，2009.(ZHU Jinpeng. Experimental study and theoretical analysis of the mechanical properties of concrete after freezing and thawing[M. S. Thesis][D]. Shandong：Shandong University，2009.(in Chinese))
[18] 谢和平，陈忠辉，易 成，等. 基于工程体–地质体相互作用的接触面变形破坏研究[J]. 岩石力学与工程学报，2008，27(9)：1 767– 1 770.(XIE Heping，CHEN Zhonghui，YI Cheng，et al. Research on deformation and failure of interface based on interaction between structural body and geo-body[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(9)：1 767–1 770.(in Chinese))
[19] 冀晓东，赵 宁，宋玉普. 冻融循环作用后变形钢筋与混凝土黏结性能退化研究[J]. 工业建筑，2010，40(1)：87–91.(JI Xiaodong，ZHAO Ning，SONG Yupu. Experimental study on bond behavior?s deterioration between deformed steel bar and concrete after freezing and thawing[J]. Industrial Construction，2010，40(1)：87–91.(in Chinese))
2014, Vol. 33 
