【摘要】：目前對(duì)裂隙巖體的損傷模型研究主要集中在以下兩個(gè)方面:一是以僅考慮裂隙長(zhǎng)度、傾角及間排距等幾何性質(zhì)的幾何損傷理論;二是同時(shí)考慮裂隙幾何參數(shù)及力學(xué)參數(shù)的損傷理論。本文在對(duì)周期性裂隙的巖體力學(xué)特性進(jìn)行研究的基礎(chǔ)上,更進(jìn)一步地研究了任意非貫通裂隙對(duì)巖體力學(xué)特性的影響,得到的主要成果如下:(1)從含單條非貫通裂隙的巖體入手,從能量角度出發(fā)推導(dǎo)出了由單條裂隙引起的損傷變量計(jì)算公式,通過考慮裂隙間的相互作用,求解出了單排及多排非貫通平行裂隙的應(yīng)力強(qiáng)度因子和損傷變量。應(yīng)用平面彈性力學(xué),給出了任意多裂隙的應(yīng)力強(qiáng)度因子的計(jì)算公式,并得到多條裂隙相互作用關(guān)系式。(2)建立多裂隙的應(yīng)力強(qiáng)度因子算例,多條裂隙的相互作用與其幾何相對(duì)位置及傾角有關(guān)。兩條裂隙的外側(cè)尖端A、D的應(yīng)力強(qiáng)度因子受相互作用影響較內(nèi)側(cè)尖端B、C的小。平行裂隙間的相互影響與裂隙間距有關(guān),且隨著裂隙間距的增大,計(jì)算所得的應(yīng)力強(qiáng)度因子值都趨于不考慮裂隙相互影響時(shí)的應(yīng)力強(qiáng)度因子值。(3)根據(jù)裂隙的相對(duì)幾何位置和傾角變化,進(jìn)行不同疊加后的應(yīng)力場(chǎng)可分別產(chǎn)生增強(qiáng)與減弱兩種效應(yīng),當(dāng)相鄰裂隙尖端處于加強(qiáng)區(qū)時(shí),其應(yīng)力強(qiáng)度因子將會(huì)變大,反之變小。(4)在壓剪應(yīng)力作用下,兩條裂隙間距越小,裂隙尖端的應(yīng)力場(chǎng)越復(fù)雜,裂隙間的相互作用就越強(qiáng),這說明在同一外部條件下,多裂隙巖體更容易發(fā)生由裂紋引起的破壞。(5)建立了兩條任意非貫通裂隙的巖體損傷模型,并獲得了兩條任意非貫通裂隙模型的損傷變量。將兩條任意非貫通裂隙模型設(shè)定為兩條垂直距離為零的平行裂隙的情況,計(jì)算出的損傷變量與已知文獻(xiàn)的計(jì)算結(jié)果進(jìn)行對(duì)比,結(jié)果較為吻合,說明了本模型的合理性。
[Abstract]:At present, the research on damage model of fractured rock mass is mainly focused on the following two aspects: one is based on the geometric damage theory which only considers the geometric properties of crack length, dip angle and spacing; The second is the damage theory which considers the geometric and mechanical parameters of fracture at the same time. Based on the study of the mechanical properties of rock mass with periodic fractures, this paper further studies the influence of any non-penetrating fracture on the mechanical properties of rock mass. The main results obtained are as follows: (1) starting with the rock mass with single non-perforated fracture, The formula of damage variable caused by single fracture is derived from the angle of energy. The stress intensity factor and damage variable of single row and multiple rows of non-penetrating parallel fractures are calculated by considering the interaction between fractures. In this paper, the formula of stress intensity factor of arbitrary multiple fractures is given by using plane elasticity, and the formula of interaction between multiple fractures is obtained. (2) an example of stress intensity factor of multiple fractures is established. The interaction of multiple fractures is related to their geometric relative position and inclination. The stress intensity factor of the lateral tip of the two fractures is less affected by the interaction than that of the inner tip of BHOC. The interaction between parallel fractures is related to the spacing of fractures, and with the increase of the spacing of fractures, The calculated values of the stress intensity factors tend to be the values of the stress intensity factors without considering the interaction of fractures. (3) according to the relative geometric position and the dip angle of the fractures, the stress fields after different stacking can produce two kinds of effects, which are strengthening and weakening, respectively. When the adjacent crack tip is in the strengthening zone, the stress intensity factor will become larger, and vice versa. (4) the smaller the spacing between the two fractures, the more complex the stress field at the crack tip, and the stronger the interaction between the fractures. This shows that the damage caused by cracks is more likely to occur in multifissured rock mass under the same external conditions. (5) two damage models of arbitrary non-penetrating fractures are established and the damage variables of two arbitrary non-penetrating fracture models are obtained. In this paper, two arbitrary nonpenetrating fracture models are set to two parallel fractures with zero vertical distance. The calculated damage variables are compared with the results of known literatures. The results show that the model is reasonable.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TU45
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本文編號(hào)：2133560