綜放沿空巷道頂部錨桿剪切變形分析

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1、第30卷第6期煤炭學(xué)報(bào)Vol.30No.62005年12月JOURNALOFCHINACOALSOCIETYDec12005文章編號(hào):0253-9993(2005)06-0681-04綜放沿空巷道頂部錨桿剪切變形分析繆協(xié)興,茅獻(xiàn)彪,朱川曲,劉衛(wèi)群(中國(guó)礦業(yè)大學(xué),江蘇徐州221008)摘要:針對(duì)煤礦大量采用的小煤柱錨網(wǎng)支護(hù),尤其是綜放沿空巷道錨網(wǎng)支護(hù),在巷道圍巖大變形過(guò)程中,錨桿可能會(huì)承受較大的剪切變形情況,從理論上分析了綜放沿空巷道頂部全長(zhǎng)錨固錨桿承受剪切變形的機(jī)理,并用數(shù)值模擬的方法計(jì)算出了其錨桿上的剪切力分布、最大剪切力和最大剪切應(yīng)力.計(jì)算分析表明:在圍巖大變形情況下,綜放沿空巷道頂

2、部錨桿上的最大剪切應(yīng)力有可能接近或超過(guò)其材料的許用剪切應(yīng)力,此時(shí)錨桿的剪切作用效應(yīng)將不可忽視.關(guān)鍵詞:綜放沿空巷道;錨桿支護(hù);剪切變形;錨桿剪斷分析中圖分類號(hào):TD35316文獻(xiàn)標(biāo)識(shí)碼:AAnalysisonshearingdeformationofroofsupportboltingob2sideentryoffully2mechanizedcavingfaceMIAOXie2xing,MAOXian2biao,ZHUChuan2qu,LIUWei2qun(ChinaUniversityofMiningandTechnology,Xuzhou221008,China)Abstract:

3、Theboltprobablysupportslargershearingdeformationinthecourseofhugedeformationofroadwaysur2roundingrock,forinstancethecablebolts2metalmeshreinforcementofsmallpillaradoptedlargelyincoalmine,es2peciallythatingob2sideentryoffully2mechanizedcavingface(FCF),themechanismthatthefull2columnroofsupportbolts

4、ustainsshearingdeformationingob2sideentryofFCFwasanalyzedbytheoreticalresearch,andtheshearingstressdistribution,themaximumshearingforceandthemaximumshearingstressinboltswereobtainedwiththehelpofnumericalsimulation.Itisindicatedthatthemaximumshearingstressoftheroofsupportboltingob2sideentryofFCFwi

5、llapproachorexceedtheallowableshearingstressofboltmaterialsinconditionoflargede2formationinsurroundingrock,andhere,theshearingeffectofboltisnottobeneglected.Keywords:gob2sideentryoffully2mechanizedcavingface;boltsupport;shearingdeformation;boltsnipanalysis[1～3][4][5]隨著煤巷錨桿支護(hù)技術(shù)的成熟和普及,綜放沿空巷道(包括沿空掘巷

6、和沿空留巷)也大多采用錨、索、網(wǎng)聯(lián)合支護(hù)技術(shù).大多數(shù)綜放沿空巷道都采用沿底掘進(jìn),煤柱或充填巷幫寬僅為3～5m,也就是綜放沿空巷道具有頂板為煤層、煤柱小、斷面大等顯著特征.實(shí)踐證明,綜放沿空錨桿支護(hù)巷道受采動(dòng)影響時(shí),一般具有大變形動(dòng)壓特征.尤其對(duì)于巷道頂板來(lái)說(shuō),由于煤柱小(充填體寬度更小),受動(dòng)壓影響時(shí),頂板會(huì)向采空區(qū)側(cè)發(fā)生顯著傾斜,即類似于懸壁梁式的彎曲下沉變形.受這種顯著彎曲變形作用的頂部錨桿,特別是全長(zhǎng)錨固支護(hù)錨桿,其變形已不再是簡(jiǎn)單的拉伸狀態(tài),而是拉、剪、彎組合變形狀態(tài).如果錨桿支護(hù)方位參數(shù)設(shè)計(jì)不合理,錨桿可能會(huì)受顯著剪切力作用,甚至可能會(huì)發(fā)生剪切斷裂,因而收稿日期:2005-04

7、-01基金項(xiàng)目:國(guó)家杰出青年科學(xué)基金資助項(xiàng)目(50225414);國(guó)家自然科學(xué)基金重大資助項(xiàng)目(50490270);國(guó)家自然科學(xué)基金資助項(xiàng)目(50374065)作者簡(jiǎn)介:繆協(xié)興(1959-),男,江蘇江陰人,教授,博士生導(dǎo)師.E-mail:xxmiao@cumt1edu1cn682煤炭學(xué)報(bào)2005年第30卷失去錨桿原有的拉緊支護(hù)功能.本文針對(duì)綜放沿空巷道礦壓特征,從理論和數(shù)值模擬兩個(gè)方面分析綜放沿空巷道頂部錨桿的剪切變形機(jī)理.1綜放