【摘要】：結(jié)構(gòu)面控制著巖石地基、巖石邊坡和地下洞室圍巖的變形與穩(wěn)定,是巖體力學(xué)性質(zhì)復(fù)雜性的根源。由于結(jié)構(gòu)面密集且分布不均勻、結(jié)構(gòu)面之間相互交錯以及空間分布的隨機性,使得節(jié)理巖體變形特性表現(xiàn)出顯著的非均勻性、各向異性、尺寸效應(yīng)和隨機效應(yīng)。深入研究節(jié)理巖體的變形特性,對充分利用巖體、有針對性的加固巖體具有重要的理論和工程意義。目前獲取節(jié)理巖體變形參數(shù)的手段主要有工程經(jīng)驗法、現(xiàn)場試驗法、解析法和數(shù)值試驗法。國內(nèi)外學(xué)者對節(jié)理巖體的變形特性做了很多研究,但仍然存在以下不足：(a)解析法能很好的解釋規(guī)則且貫穿性節(jié)理的變形特性,但缺乏對非貫穿節(jié)理變形機理的合理模擬；(b)三維結(jié)構(gòu)面網(wǎng)絡(luò)模型的離散存在較大難度,所以基于三維結(jié)構(gòu)面網(wǎng)絡(luò)離散模擬的成果較少,更缺乏對三維等效參數(shù)的隨機性分析；(c)數(shù)值試驗方法高效,但缺乏與巖體現(xiàn)場變形試驗結(jié)果的對比和驗證；(d)節(jié)理巖體各向異性對水工結(jié)構(gòu),特別是對高拱壩-壩基系統(tǒng)工作狀態(tài)的影響研究鮮有報道。本文針對這些主要問題,采用理論分析、室內(nèi)外試驗、數(shù)值模擬與工程經(jīng)驗相結(jié)合的方法,從以下幾個方面展開研究：(1)節(jié)理巖體變形的各向異性。對于規(guī)則貫穿節(jié)理巖體,基于應(yīng)變疊加原理,推導(dǎo)了等效彈性本構(gòu),并分析了幾種特殊貫穿節(jié)理巖體變形的空間特性。結(jié)果表明,層狀節(jié)理巖體變形特性在空間上關(guān)于節(jié)理法線方向軸對稱,柱狀節(jié)理巖體變形特性在空間上關(guān)于平面對稱,含三組正交節(jié)理的巖體特性在空間上關(guān)于平面對稱。通過非貫穿節(jié)理巖體的精細模擬,驗證了巖橋具有釘梢和抗剪的作用,并基于應(yīng)變疊加原理、應(yīng)力一致原則、應(yīng)力分擔(dān)原則以及應(yīng)變一致原則,引入巖橋影響高度的概念,推導(dǎo)了節(jié)理巖體的變形等效本構(gòu)關(guān)系。(2)節(jié)理巖體變形的隨機效應(yīng)。本文借助蒙特卡洛方法,生成了具有代表性的結(jié)構(gòu)面網(wǎng)絡(luò)樣本,基于復(fù)合單元法,建立了三維柔度張量的數(shù)值試驗方法,以SW水電站的復(fù)雜節(jié)理巖體為研究對象,對巖體三維柔度張量的各個分量進行統(tǒng)計分析,探討節(jié)理巖體變形參數(shù)的隨機特性。結(jié)果表明,每組結(jié)構(gòu)面網(wǎng)絡(luò)樣本的三維等效柔度張量由于結(jié)構(gòu)面的分布不同而不同,但是各個分量均服從一定的統(tǒng)計規(guī)律。以SW水電站左岸弱風(fēng)化節(jié)理巖體為例,其三維柔度張量最接近服從對數(shù)正態(tài)分布。(3)基于巖體現(xiàn)場變形試驗的結(jié)構(gòu)面參數(shù)反演和區(qū)域巖體等效柔度張量的預(yù)測。利用巖體現(xiàn)場變形試驗的結(jié)果,結(jié)合結(jié)構(gòu)面地質(zhì)調(diào)查、巖石室內(nèi)試驗,采用結(jié)構(gòu)面網(wǎng)絡(luò)離散模擬的數(shù)值試驗法對結(jié)構(gòu)面以法剛切剛為主控的變形參數(shù)進行反演,獲得試驗點位置的等效柔度張量并預(yù)測區(qū)域巖體的等效柔度張量。用反演得到的柔度張量進行剛性承壓板試驗驗證,證明了反演結(jié)果的可靠性。(4)拱壩壩基巖體多尺度結(jié)構(gòu)面的數(shù)值分析模型。該模型結(jié)合等效模擬和離散模擬的優(yōu)勢,既可以考慮斷層等定位結(jié)構(gòu)面,也可以考慮Ⅳ級和Ⅴ級隨機結(jié)構(gòu)面,并成功運用于QBT水電站拱壩-壩基系統(tǒng)的變形分析。結(jié)果表明：當(dāng)考慮隨機結(jié)構(gòu)面造成的各向異性特性時,該拱壩及壩肩巖體位移分布發(fā)生了變化,壩肩巖體順河向位移減小,拱端位移夾角增大,拱壩壩肩穩(wěn)定條件變好；但拱壩變形更加扁平化,拱壩應(yīng)力變壞,需要引起注意。本文研究成果對于節(jié)理巖體變形規(guī)律研究、參數(shù)合理化取值及水工結(jié)構(gòu)穩(wěn)定分析評價具有重要意義。
[Abstract]:The structural surface controls the deformation and stability of rock foundation, rock slope and surrounding rock of underground cavity, and is the source of the complexity of mechanical properties of rock mass. The deformation characteristics of jointed rock mass show remarkable non-uniformity, anisotropy, size effect and random effect because of the dense and uneven distribution of the structure surface and the randomness of the spatial distribution between the structural planes. In depth study of the deformation characteristics of jointed rock mass, it has important theoretical and engineering significance for making full use of rock mass and targeted reinforcing rock mass. At present, the means of obtaining the deformation parameters of jointed rock mass mainly include engineering experience method, field test method, analytical method and numerical test method. The deformation characteristics of jointed rock mass have been studied by scholars both at home and abroad. However, the following shortages still exist: (a) the analytical method can well explain the deformation characteristics of the regular and penetrating joints, but lack reasonable simulation of the non-penetrating joint deformation mechanism; (b) the discrete existence of the three-dimensional structural plane network model is more difficult, so that the results of discrete simulation based on the three-dimensional structural plane network are less, and the randomness analysis of the three-dimensional equivalent parameter is more lacked; and (c) the numerical test method is high-efficiency, However, the comparison and verification of the results of field deformation test of rock mass are lacking, and (d) the influence of the anisotropy of jointed rock mass on hydraulic structure, especially on the working state of high arch dam-dam foundation system is seldom reported. In view of these main problems, the paper adopts the method of theoretical analysis, indoor and outdoor test, numerical simulation and engineering experience, and studies the following aspects: (1) anisotropy of joint rock mass deformation. On the basis of the principle of strain superposition, the equivalent elastic structure is derived for regular penetration of jointed rock mass, and the spatial characteristics of several special penetrating jointed rock mass deformation are analyzed. The results show that the deformation characteristics of the layered jointed rock mass are symmetric in the direction of the normal direction of the joint, the deformation characteristics of the columnar joint rock mass are symmetric about the plane in space, and the rock mass properties of the three groups of orthogonal joints are spatially symmetrical about the plane. Through the fine simulation of non-penetrating jointed rock mass, it is verified that the rock bridge has the function of nail tip and shear, and based on the principle of strain superposition, the principle of stress consistency, the principle of stress sharing and the principle of strain coincidence, the concept of influence height of rock bridge is introduced. The deformation equivalence of jointed rock mass is deduced. (2) Random effect of deformation of jointed rock mass. In this paper, by means of Monte Carlo method, a representative structural plane network sample is generated. Based on the composite element method, a numerical test method of three-dimensional flexibility tensor is established, and the complex jointed rock mass of SW hydropower station is used as the research object. The random characteristics of the deformation parameters of jointed rock mass are studied by statistical analysis of each component of the three-dimensional soft-degree tensor of rock mass. The results show that the three-dimensional equivalent flexibility tensor of each group of structural plane network samples is different from the distribution of the structural plane, but each component is subject to certain statistical rules. Based on the weak weathered jointed rock mass on the left bank of SW hydropower station, the three-dimensional flexibility tensor is closest to the lognormal distribution. (3) Based on the structural plane parameter inversion of rock mass on-site deformation test and the prediction of the equivalent flexibility tensor of rock mass. Based on the results of site deformation test of rock mass, combined with the structural surface geological survey and rock indoor test, the deformation parameters of the structural plane, which are mainly controlled by the structural surface network, are inverted by the numerical test method of the structural plane network discrete simulation. The equivalent flexibility tensor of the position of the test point is obtained and the equivalent flexibility tensor of the area rock mass is predicted. The reliability of the inversion results is proved by using the flexibility tensor obtained by inversion to test the rigid pressure bearing plate. (4) Numerical analysis model of multi-scale structural surface of dam foundation rock mass. Combined with the advantages of equivalent simulation and discrete simulation, the model can take into account the structural plane of fault and so on, and also consider the random structure surface of grade 鈪，

本文編號：2274269