Tests on bond strength between grout and tendon of soil anchors
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摘要: 国内外对锚杆筋体与浆体黏结强度的研究成果极少。3项工程64个土层锚索现场试验成果表明：①各锚筋与浆体极限黏结力的离散程度很大,普遍存着孤低现象,据此反算得到的浆筋黏结强度的离散程度很大,离散程度与黏结长度无关,与锚筋数量及张拉工艺相关;②浆筋黏结强度与地层、注浆工艺及锚筋数量无关,带套管成孔、改善孔内清洁程度可明显提高;③浆体设计强度与浆筋黏结强度的对应关系无法验证,实际强度及锚筋外形对浆筋黏结强度的影响亦无法验证;④浆筋黏结强度的发挥程度随着黏结长度的增加而有所下降;⑤黏结长度3~6 m时,浆筋黏结强度标准值为0.744~0.664 MPa;⑥土层锚索黏结长度不宜短于8 m;⑦单根锚索钢绞线数量不宜为2条。Abstract: The research results about the bond strength between anchor tendon and grout are few. The test results of 64 soil anchors in 3 projects show that: (1) The dispersion degree of the ultimate bond capacity between grout and tendon is tremendous, and its solitary-low phenomenon is widespread. The dispersion degree has nothing to do with the bond length and is related with the quantity of tendons and tension technique, so that of the calculated bond strength of grout-tendon is tremendous. (2) The bond strength of grout-tendon is not related with the in-situ conditions, grout techniques and quantity of tendons, but is able to be improved when drilling with casing pipes and improving the cleanliness of the hole. (3) The relationship between the grout-tendon bond strength and the grout design strength cannot be verified, neither is the effect of actual strength of grout and tendon sharp on the bond strength of grout-tendon. (4) The exerting degree of bond strength slightly decreases with the increase of bond length. (5) The characteristic values of bond strength of grout-tendon are 0.744~0.664 MPa under the bond length of 3~6 m. (6) The bond length of soil anchors should be more than 8 m. (7) The number of tendons in the single anchor should not be 2.
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Keywords:
- grout /
- anchor tendon /
- bond strength /
- bond length /
- ultimate bond capacity /
- grout strength /
- tendon sharp /
- characteristic value
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[1] 付文光. 岩土工程规范杂议[M]. 北京: 中国建筑工业出版社, 2016: 123-125.
(FU Wen-guang.Discussion about Geotechnical Standards[M]. Beijng: China Architecture & Building Press, 2016: 123-125. (in Chinese))[2] CECS22—2005 岩土锚杆(索)技术规程[S]. 2005.
(CECS22—2005 Technical specification for ground anchors[S]. 2005. (in Chinese))[3] GB 50330—2013 建筑边坡工程技术规范[S]. 2013. (GB 50330—2013 Technical code for building slope engineering[S]. 2013. (in Chinese)) [4] GB/T 5224—2014 预应力混凝土用钢绞线[S]. 2014.
(GB/T 5224—2014 Steel strand for prestressed concrete[S]. 2014. (in Chinese))[5] BS 8081:1989. British standard code of practice for ground anchoragesS 8081:1989. British standard code of practice for ground anchorages[S]. BSI, 1989. [6] 付文光, 任晓光. 拉力分散型锚索的研究与应用研究报告[R]. 北京: 中国京冶工程技术有限公司, 2016.
(FU Wen-guang, REN Xiao-guang.Research report about research and application of dispersed tensile anchor[R]. Beijing: China JingYe Engineering Co., Ltd, 2016. (in Chinese))[7] JGJ/T 282—2012. 高压喷射扩大头锚杆技术规程GJ/T 282—2012. 高压喷射扩大头锚杆技术规程[S]. 2012.
(JGJ/T 282—2012. Technical specification for underreamed anchor by jet groutingGJ/T 282—2012. Technical specification for underreamed anchor by jet grouting[S]. 2012. (in Chinese))[8] GB50021—2001(2009年版). 岩土工程勘察规范[S]. 2009.(GB50010—2001(2009 edition). Code for investigation of geotechnical engineering[S]. 2009. (in Chinese))
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