【摘要】：自上世紀(jì)50年代中期以來(lái),巖石隧道掘進(jìn)機(jī)以其施工環(huán)境友好、施工速度快、對(duì)圍巖的擾動(dòng)小以及長(zhǎng)隧道施工的經(jīng)濟(jì)效益顯著等優(yōu)點(diǎn),已廣泛應(yīng)用于各國(guó)地下工程的建設(shè)。對(duì)于高放廢物處置庫(kù)而言,圍巖損傷特征是影響其長(zhǎng)期穩(wěn)定性及運(yùn)行安全性的重要因素,圍巖損傷的產(chǎn)生與演化和諸多因素相關(guān),以TBM法為主的機(jī)械開挖方法具有圍巖擾動(dòng)小等優(yōu)點(diǎn),成為高放廢物處置庫(kù)和地下實(shí)驗(yàn)室大量高標(biāo)準(zhǔn)井巷工程選用的主要開挖方法。因此,對(duì)TBM刀盤滾刀作用下的圍巖破裂和損傷特性以及節(jié)理間距對(duì)破巖的影響進(jìn)行研究,是研究處置庫(kù)的損傷分布情況以及后續(xù)的核素運(yùn)移模式的基礎(chǔ),具有重要意義。本文結(jié)合室內(nèi)全尺寸滾刀線性切割破巖實(shí)驗(yàn),采用熒光法研究了盤形滾刀作用下不同刀間距(70mm、80mm、90mm、100mm)對(duì)北山花崗巖裂紋擴(kuò)展特征的影響規(guī)律。針對(duì)滾刀下巖樣破碎特征,借助CorelDraw和Image J軟件對(duì)裂紋熒光圖進(jìn)行分區(qū)及統(tǒng)計(jì)分析,并與巖樣各區(qū)的波速損傷指標(biāo)進(jìn)行對(duì)比。另外,結(jié)合室內(nèi)全尺寸滾刀線性切割破巖實(shí)驗(yàn),研究了不同節(jié)理間距對(duì)TBM滾刀力及破壞模式的影響。研究發(fā)現(xiàn),同一刀間距作用下巖樣各區(qū)的破碎程度存在較大的差異;不同刀間距作用下,巖樣各區(qū)裂紋擴(kuò)展的深度、長(zhǎng)度及面積隨著刀間距的增大呈現(xiàn)增大的趨勢(shì),且各區(qū)所占的比例隨刀間距變化而不同。針對(duì)北山花崗巖,刀間距為70~100mm時(shí),圍巖損傷范圍小于50mm。裂紋擴(kuò)展模式對(duì)TBM破巖效率、破巖損傷以及巖片形狀有顯著影響。主要從三向力、裂紋的擴(kuò)展模式和巖片等角度分析了節(jié)理間距對(duì)滾刀破巖的影響。結(jié)果表明:節(jié)理間距100mm的巖體切入所需要的推力小于完整巖石的推力,節(jié)理間距400mm的巖體破巖過(guò)程中推力有一個(gè)突變的過(guò)程。節(jié)理間距100mm巖體滾刀作用下存在兩種破壞模式,節(jié)理間距400mm的巖體破巖過(guò)程則包括了正常破巖和節(jié)理面影響破巖兩個(gè)過(guò)程,并且節(jié)理對(duì)了豎向主裂紋向節(jié)理面擴(kuò)展有加劇的作用。節(jié)理面下方巖石較完整,節(jié)理面阻礙了裂紋朝節(jié)理面下方巖石傳播。
[Abstract]:Since the middle of 1950s, rock tunnel tunneling machine has been widely used in the construction of underground projects in various countries because of its advantages of friendly construction environment, fast construction speed, small disturbance to surrounding rock and remarkable economic benefits of long tunnel construction. The damage characteristics of surrounding rock is an important factor affecting the long-term stability and operation safety of HLW, and the generation of surrounding rock damage is related to evolution and many factors. The mechanical excavation method based on TBM method has the advantages of small disturbance of surrounding rock and so on. It has become the main excavation method for high-level radioactive waste disposal storehouse and a large number of underground laboratory high standard shaft and roadway projects. Therefore, it is of great significance to study the fracture and damage characteristics of surrounding rock and the effect of joint spacing on rock breaking under the action of TBM cutter hob, which is the basis of studying the damage distribution in the repository and the subsequent nuclide migration model. In this paper, the influence of different cutter spacing (70mm / 80mm / 90mm / 100mm) on crack propagation characteristics of Beishan granite under the action of disk hob is studied by fluorescence method combined with laboratory experiments of linear cutting rock breaking with full-scale hob. According to the characteristics of rock sample fragmentation under hob, the crack fluorescence map is divided and statistically analyzed by using CorelDraw and Image J software, and the wave velocity damage index of rock sample is compared with that of rock sample. In addition, the influence of different joint spacing on the force and failure mode of TBM hob is studied. It is found that there is a great difference in the degree of fragmentation of rock samples under the same knife spacing, and the depth, length and area of crack propagation in rock samples show a trend of increasing with the increase of tool spacing, and the depth, length and area of crack propagation in rock samples are increased with the increase of blade spacing. And the proportion of each region varies with the distance between knives. For Beishan granite, the damage range of surrounding rock is less than 50 mm when the tool spacing is 70~100mm. The crack propagation model has a significant effect on the rock breaking efficiency, rock breaking damage and the shape of rock fragments of TBM. The influence of joint spacing on the breaking rock of hob is analyzed from the angles of triaxial force, crack propagation model and rock sheet. The results show that the thrust of the rock mass with joint spacing 100mm is less than that of the whole rock mass, and the thrust of the rock mass with joint spacing 400mm has a sudden process. There are two failure modes under the action of joint-spacing 100mm rock hob. The rock mass breaking process of joint-spacing 400mm includes two processes: normal rock breaking and joint surface influencing rock breaking. And the joint can accelerate the propagation of the vertical main crack to the joint surface. The rock below the joint surface is relatively complete, and the joint surface prevents the crack from spreading to the rock below the joint surface.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U455.31;U456
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本文編號(hào)：2129789