本文關(guān)鍵詞： 裂隙巖體 滲透水壓 判定準(zhǔn)則 裂隙閉合形態(tài) 損傷因子 蠕變損傷模型 時(shí)效損傷劣化　出處：《中南大學(xué)》2014年博士論文　論文類型：學(xué)位論文

【摘要】：巖體中裂隙對(duì)其力學(xué)特征的影響不可忽略,裂隙巖體在應(yīng)力場或流固耦合影響下的斷裂破壞機(jī)制與蠕變損傷機(jī)理是巖體力學(xué)研究的主要內(nèi)容之一,對(duì)于巖體中工程項(xiàng)目安全順利、高速有效地開展,具有重要的理論價(jià)值和指導(dǎo)意義 本文較為系統(tǒng)地開創(chuàng)性研究了應(yīng)力場和流固耦合影響下裂隙巖體的斷裂破壞機(jī)制與蠕變損傷機(jī)理,以往研究裂隙巖體斷裂破壞機(jī)制時(shí)大多局限于裂隙尖端微裂紋的發(fā)育模式與力學(xué)機(jī)理,而對(duì)其強(qiáng)度變化規(guī)律較少涉及,因而不可避免了忽視了滑動(dòng)裂紋模型理論在解釋與分析裂隙尖端微裂紋發(fā)育模式與力學(xué)機(jī)理方面的適用范圍；同時(shí),對(duì)于巖體蠕變損傷機(jī)理方面的研究工作,主要集中在非線性組合模型上,而對(duì)裂隙巖體蠕變變形的非線性特征并未給予足夠的重視,因而常犯線性元件非線性描述的低級(jí)錯(cuò)誤。本文針對(duì)上述實(shí)際情形,基于滑動(dòng)裂紋模型理論解與實(shí)測結(jié)果之間的差異,首次提出了滑動(dòng)裂紋模型理論在解釋與分析張開裂隙斷裂破壞機(jī)理方面具有局限性的觀點(diǎn),并結(jié)合彈性力學(xué)理論,給出了壓縮條件下扁橢圓孔邊界上環(huán)向拉伸應(yīng)力的解析解；同時(shí),根據(jù)流固耦合影響下,裂隙面上的正應(yīng)力分布特征,創(chuàng)造性地提出了裂隙巖體內(nèi)高低滲透水壓判定準(zhǔn)則,并將常見巖土工程問題簡化為三種力學(xué)模型,在數(shù)值領(lǐng)域內(nèi)分別對(duì)其進(jìn)行了計(jì)算和分析工作；另一方面,將損傷因子引入流變學(xué)研究工作中,在基本流變?cè)A(chǔ)上構(gòu)建了損傷元件模型,并將裂隙塑性體和加速蠕變體置入組合蠕變損傷模型中,建立了考慮原生節(jié)理影響的非線性黏彈塑性蠕變損傷模型。其主要研究成果如下所述： (1)壓剪復(fù)合應(yīng)力環(huán)境下,由于忽略壓應(yīng)力在裂隙尖端應(yīng)力場的力學(xué)作用,而僅考慮其在裂紋面上產(chǎn)生滑動(dòng)摩擦阻力的作用效果,并結(jié)合最大周向拉應(yīng)力理論,使得滑動(dòng)裂紋模型理論很好地解釋了壓剪復(fù)合應(yīng)力下裂隙尖端翼型張拉裂紋的發(fā)育機(jī)制。但是研究發(fā)現(xiàn),實(shí)測裂隙體強(qiáng)度變化規(guī)律與該理論解之間存在顯著差異,結(jié)合裂隙體形態(tài)特征及力學(xué)響應(yīng)規(guī)律,首次提出了滑動(dòng)裂紋模型理論在預(yù)測張開裂隙模型破壞機(jī)制方面具有局限性的觀點(diǎn),然后根據(jù)彈性力學(xué)在橢圓孔洞問題上的解析解,給出了單向應(yīng)力下扁橢圓孔邊界上的力學(xué)響應(yīng)規(guī)律,解釋了張開裂隙試件在單軸壓縮實(shí)驗(yàn)條件下的變形破壞機(jī)理。 (2)在PFC數(shù)值計(jì)算平臺(tái)上,基于fish語言改編了白帶Fish Tank模型程序,實(shí)現(xiàn)了增強(qiáng)Fish Tank模型的開發(fā),然后在程序自帶Fish Tank程序和增強(qiáng)Fish Tank程序上分別進(jìn)行了多裂隙與單裂隙模型的計(jì)算和分析工作,并將數(shù)值計(jì)算結(jié)果與實(shí)測結(jié)果相對(duì)比,表明了滑動(dòng)裂紋模型理論在解釋張開裂隙尖端微裂紋發(fā)育模式與擴(kuò)展機(jī)制方面局限性的存在。 (3)研究了數(shù)值條件下閉合裂隙巖體模型的構(gòu)建方法與技術(shù),并在PFC2D數(shù)值計(jì)算平臺(tái)上完成了閉合裂隙數(shù)值模型的單向及雙向加載試驗(yàn)研究,通過對(duì)比張開裂隙模型的力學(xué)響應(yīng)規(guī)律,進(jìn)一步確認(rèn)了裂隙閉合形態(tài)對(duì)其斷裂破壞模式影響性的存在。 (4)滲流場中裂隙巖體的力學(xué)特性及水巖作用機(jī)理是巖石力學(xué)領(lǐng)域關(guān)注的前沿方向,并逐漸成為理論和實(shí)驗(yàn)研究的熱門課題；同時(shí),滲流場的存在和改變,也是導(dǎo)致巖體工程失穩(wěn),甚至發(fā)生大規(guī)模地質(zhì)災(zāi)害的重要原因,因此在滲流場中進(jìn)行卸荷條件下裂隙巖體響應(yīng)及巖土工程穩(wěn)定分析,具有廣闊的應(yīng)用前景和學(xué)術(shù)價(jià)值。根據(jù)滲流場與應(yīng)力場耦合作用下裂隙巖體內(nèi)裂紋面上的應(yīng)力分布狀態(tài),提出了高低滲透水壓環(huán)境判定準(zhǔn)則,并給出了相應(yīng)滲透水壓下的裂隙巖體斷裂破壞機(jī)理,并將常見巖土工程問題簡化為三種力學(xué)模型：豎向加載、側(cè)向卸荷與增大滲透壓,并完成了相應(yīng)力學(xué)條件下裂隙體模型的計(jì)算與分析工作。 (5)蠕變性是深部巖體巷道的典型變形特征,而典型巖樣的室內(nèi)加載試驗(yàn)是研究巖體蠕變變形規(guī)律的主要技術(shù)方法,基于室內(nèi)典型巖樣的蠕變實(shí)驗(yàn)研究深部巖體巷道蠕變變形機(jī)制是目前流變學(xué)研究熱點(diǎn),并具有重要的工程意義和學(xué)術(shù)價(jià)值。在蠕變模型研究基礎(chǔ)上,結(jié)合巖石試件的蠕變損傷演化機(jī)制,引入損傷力學(xué)中的損傷因子來描述由時(shí)效損傷劣化效應(yīng)帶來的巖石非線性變形規(guī)律,在物理學(xué)與流變學(xué)上實(shí)現(xiàn)真正意義的參數(shù)非線性化統(tǒng)一描述,并以此為基礎(chǔ),完成了經(jīng)典蠕變模型和基本流變?cè)渥儞p傷變形特征的非線性描述,然后引入裂隙塑性體來描述原生裂隙在蠕變條件下的變形機(jī)制,同時(shí)引入非線性加速蠕變體,組成考慮原生節(jié)理影響的變參數(shù)非線性蠕變損傷模型,并給出組合模型相應(yīng)應(yīng)力水平下的蠕變狀態(tài)方程；最后基于東鄉(xiāng)銅礦砂質(zhì)頁巖蠕變實(shí)驗(yàn)對(duì)該蠕變損傷模型進(jìn)行了驗(yàn)證和分析。
[Abstract]:Influence of rock fracture on the mechanical characteristics of fractured rock mass can not be ignored, the stress field and fracture fluid solid coupling under the influence of the failure mechanism and creep damage mechanism is one of the main contents of the research on rock mechanics, rock mass for the project is safe and smooth, high speed effectively, and has important theoretical value and guiding significance
Study on the stress field and failure mechanism and damage mechanism of creep fracture of fractured rock mass under the effect of fluid solid coupling is systematically created in this paper, previous research of fracture failure mechanism of fractured rock mass is mostly limited to development model and mechanism of crack tip micro cracks, and the strength variation of less involved, thus inevitably neglect the scope of application of the sliding crack model theory in the interpretation and analysis of the crack tip micro crack development model and mechanics mechanism; at the same time, the research work on the creep damage mechanism of rock, mainly concentrated in the non linear combination model, and the nonlinear characteristics of the deformation of fractured rock creep did not give enough attention, so often make nonlinear description the linear element of low-level error. In this paper, according to the actual situation, based on the difference between the sliding crack model theory and measured results, For the first time put forward the sliding crack model theory in the analysis and interpretation of fracture opening fracture failure mechanism of view has its limitation, and combined with the theory of elastic mechanics, the analytical boundary given flat oval ring under compression to tensile stress solution; at the same time, according to the effect of fluid solid coupling, stress distribution is on the cracked surface, creatively put forward the fissure rock high seepage pressure criterion, and the common geotechnical engineering problem is simplified to three kinds of mechanical models, the numerical field has separately carried on the calculation and analysis of the work; on the other hand, the damage factor into the rheological research work, based on the basic rheological element construction the damage component model, and the fracture plastic body and accelerated creep into combined creep damage model was established, considering the nonlinear effects of primary joints visco elastoplastic creep damage model The main research results are as follows:
(1) the compressive shear stress environment, due to the neglect of pressure stress mechanical stress field in the crack tip, and considering only the sliding friction on crack surface effect, combined with the maximum circumferential stress theory, the sliding crack model well explains the shear pressure under combined stress of crack tip airfoil tensile crack development mechanism. But the study found that the law of observation of cracked body strength change and there were significant differences between the theoretical solution, combined with the fracture morphology and mechanical response of the body, are presented for the first time limitation of the sliding crack model cracking model in predicting the failure mechanism of point of view. Then according to the elastic mechanics analysis in elliptic holes on the solution, given the uniaxial stress mechanical boundary flat elliptical holes on response law, explains the cracking of specimen in uniaxial compression tests under the condition of The mechanism of deformation and failure.
(2) in the numerical calculation of PFC platform, fish language adaptation of Fish program based on the Tank model leucorrhea, realizes the development of Fish enhanced Tank model, then with calculation of multi cracks and single fracture model and analysis work of Fish Tank and enhanced Fish Tank program respectively in the program, and the results with the measured by comparing the results of numerical calculation show that the sliding crack model, the crack tip opening theory to explain the micro crack development model and expansion mechanism of limitations.
(3) to study the numerical conditions construction method and technology of closed model of fractured rock mass, and the numerical calculation of PFC2D platform to complete the test of one-way and two-way loading closed fracture numerical model, by comparing the mechanical response of open fracture model, further confirmed the existence of the fracture morphology of the crack closure effect on the model.
(4) the mechanical properties and the mechanism of water rock interaction in the field of seepage in fractured rock is one of the hot topics concerned in the field of rock mechanics, and gradually become a hot topic of theoretical and experimental research; at the same time, the seepage field of existence and change, but also lead to instability of rock engineering, an important reason or even a large scale of geological disasters, so stability analysis of fractured rock mass response and geotechnical engineering under the condition of unloading in seepage field, has broad application prospects and academic value. According to the stress distribution in the crack rock field on seepage field and stress, the level of osmotic pressure environment criterion, and gives the fracture rock mass the corresponding permeability under water pressure and the failure mechanism, and the common geotechnical engineering problem is simplified to three kinds of mechanical models: vertical load, lateral unloading and increase the osmotic pressure, and completed the corresponding mechanical conditions The calculation and analysis of the fractured body model.
(5) the creep of deep rock roadway is the typical deformation characteristics, and the indoor load test is the main method of typical rock deformation law of rock creep, mechanism of typical indoor rock creep experiment of deep rock roadway deformation is currently hot research based on rheology, and has important engineering significance and academic value. On the basis of the creep model, combined with the rock creep damage the evolution mechanism, the introduction of damage factor in damage mechanics is described by the aging damage of rock non-linear degradation law of deformation, describe the parameters in Nonlinear Unified physics and rheology on the real significance of, and on this basis, to complete the description the classical nonlinear creep model and basic rheological element creep damage deformation characteristics, and the introduction of plastic fracture to describe primary fissures in creep conditions The deformation mechanism, while the introduction of nonlinear acceleration creep, nonlinear variable parameter creep damage model considering the influence of the composition of primary joints, and gives the corresponding creep equation of state combination model of stress level; finally, based on the creep test of Dongxiang copper mine of sandy shale to validate and analysis the model of the creep damage.

【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU452

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本文編號(hào)：1539970