【摘要】：擬建的怒江馬吉高拱壩，設(shè)計(jì)壩高300m，裝機(jī)容量4200MW，為世界級(jí)高壩。拱壩的穩(wěn)定性主要靠壩肩巖體來(lái)承擔(dān)，壩肩巖體的均一性、承載能力以及穩(wěn)定性直接關(guān)系著拱壩的安全。壩肩巖體結(jié)構(gòu)特征控制著壩肩巖體的變形、破壞機(jī)制、力學(xué)性質(zhì)以及壩肩抗力體塊體邊界構(gòu)成，進(jìn)而決定著拱壩的穩(wěn)定性。因此對(duì)馬吉高拱壩兩岸壩肩巖體結(jié)構(gòu)特征進(jìn)行研究，對(duì)整個(gè)工程的可行性、安全性及經(jīng)濟(jì)性意義重大。 本文以“巖體結(jié)構(gòu)控制論”為主要指導(dǎo)思想，以右岸一條測(cè)線為例，對(duì)拱壩安全穩(wěn)定所關(guān)注的右岸壩肩巖體結(jié)構(gòu)進(jìn)行了研究，探索了一種利用地質(zhì)建模軟件從三維角度表征巖體結(jié)構(gòu)的新方法。通過(guò)本文的深入研究，得到了如下幾點(diǎn)結(jié)論： （1）研究了馬吉水電站木加甲壩址的工程地質(zhì)條件，認(rèn)為壩址區(qū)屬于貢山—福貢弧緣褶皺帶內(nèi)的丙中洛褶皺束范疇，區(qū)域構(gòu)造不發(fā)育，無(wú)深大斷裂及活斷層發(fā)育，不具備發(fā)生6.5級(jí)以上強(qiáng)震的構(gòu)造條件，新構(gòu)造運(yùn)動(dòng)主要表現(xiàn)為區(qū)域性上升運(yùn)動(dòng)；壩區(qū)屬高山峽谷地貌，兩岸岸坡基本對(duì)稱，地形完整，巖性主要為混合花崗巖、混合片麻巖，巖石堅(jiān)硬，巖體完整，巖層陡傾，適合修建拱壩。 （2）壩區(qū)內(nèi)結(jié)構(gòu)面發(fā)育，主要包括斷層、擠壓帶（面）、剪切帶、節(jié)理裂隙等。右岸無(wú)I，II級(jí)結(jié)構(gòu)面，III、IV級(jí)斷層按走向分為SE150°、SW229°和SW252°三組，延伸長(zhǎng)度都在多在200m左右，破碎帶寬度平均0.25m，組成物質(zhì)以巖屑巖塊為主少量夾泥，性質(zhì)以張扭和壓扭為主，都為陡傾角。V級(jí)結(jié)構(gòu)面為隨機(jī)裂隙，，裂隙傾角以陡傾為主，中等傾角次之，緩傾角裂隙亦見有發(fā)育。根據(jù)優(yōu)勢(shì)方向劃分了4組，裂隙性狀較好，多為剛性或著次硬性結(jié)構(gòu)面。 （3）根據(jù)規(guī)范并引入地震縱波速，RQD，和節(jié)理間距三個(gè)量化指標(biāo)對(duì)馬吉水電站右岸壩肩巖體進(jìn)行了風(fēng)化帶劃分，并利用蒙特卡羅方法按風(fēng)化段進(jìn)行了三維裂隙網(wǎng)絡(luò)模擬。 （4）利用三維地質(zhì)建模軟件對(duì)地形面、巖層、巖脈包體、風(fēng)化面、確定性的斷層、模擬出的裂隙以1:1000的比例進(jìn)行了三維地質(zhì)建模，創(chuàng)新性地提出了利用商業(yè)化軟件建立巖體結(jié)構(gòu)模型的新方法，該方法具有較強(qiáng)的推廣性。 （5）在巖體結(jié)構(gòu)三維表征的基礎(chǔ)上，對(duì)組成巖體結(jié)構(gòu)的結(jié)構(gòu)面和結(jié)構(gòu)體進(jìn)行了研究：裂隙具有上陡下緩的發(fā)育規(guī)律，裂隙間距整體上呈現(xiàn)出隨硐深增加、高程增加而變大的規(guī)律，裂隙跡長(zhǎng)多服從伽瑪分布；巖體內(nèi)裂隙相互切割形成的孤立塊體較少，提取邊長(zhǎng)為2m的巖體單元進(jìn)行研究，發(fā)現(xiàn)塊體單元?dú)w納起來(lái)主要有板片狀，條柱狀，棱錐狀，棱柱狀和復(fù)雜形狀，棱錐狀塊體比例最大，板片狀和棱柱狀次之。強(qiáng)風(fēng)化巖體屬于碎裂結(jié)構(gòu)到塊裂結(jié)構(gòu)，弱風(fēng)化上帶巖體屬于塊裂結(jié)構(gòu)和鑲嵌結(jié)構(gòu)，弱風(fēng)化下帶巖體為互層狀結(jié)構(gòu)到中厚層狀結(jié)構(gòu)，微風(fēng)化巖體為厚層狀結(jié)構(gòu)或塊狀結(jié)構(gòu)，新鮮巖體屬于巨厚層狀結(jié)構(gòu)或整體塊狀結(jié)構(gòu)。裂隙切割構(gòu)成的巖體結(jié)構(gòu)較小，控制著巖體的力學(xué)性質(zhì)，難以形成影響壩肩穩(wěn)定的邊界條件。 （6）通過(guò)透視地形面，對(duì)斷層系統(tǒng)切割形成的宏觀巖體結(jié)構(gòu)進(jìn)行了研究，壩肩巖體被斷層切割成了巨大的柱狀和層狀，與連通率最高達(dá)55.8%的緩傾坡外的裂隙共同控制著壩肩的穩(wěn)定性。結(jié)合拱壩推力方向，分析了壩肩抗力體的邊界條件，提取了底滑面和側(cè)裂面，利用三維結(jié)構(gòu)模型搜索出了6個(gè)潛在滑移塊體，并對(duì)其進(jìn)行了表達(dá)，為將來(lái)進(jìn)行壩肩穩(wěn)定性評(píng)價(jià)奠定了基礎(chǔ)。
[Abstract]:The proposed Maji high arch dam on Nujiang River is a world-class high dam with a design height of 300m and a installed capacity of 4200MW. The stability of the dam is mainly assumed by the abutment rock mass. The homogeneity, bearing capacity and stability of the abutment rock mass are directly related to the safety of the arch dam. The structural characteristics of the abutment rock mass control the deformation, failure mechanism and mechanical properties of the abutment rock mass. The stability of the arch dam is determined by the composition of the abutment resistance block boundary. Therefore, it is of great significance for the feasibility, safety and economy of the whole project to study the structural characteristics of the abutment rock mass on both sides of the Maji high arch dam.
Based on the principle of "rock mass structure cybernetics", taking a survey line on the right bank as an example, this paper studies the rock mass structure of the abutment on the right bank, which is concerned about the safety and stability of arch dams, and explores a new method to characterize the rock mass structure from a three-dimensional perspective by using geological modeling software. :
(1) The engineering geological conditions of Mujiajiajia dam site of Maji Hydropower Station are studied. It is considered that the dam site area belongs to the category of Bingzhongluo fold bundle in the Gongshan-Fugong arc margin fold belt. The regional structure is undeveloped, there are no deep and large faults and active faults, and there is no structural condition for strong earthquakes with magnitude 6.5 or above. The neotectonic movement is mainly manifested by regional ascending movement. The dam area is a high mountain and Canyon landform, the banks of both sides are basically symmetrical, the topography is complete, the lithology is mainly mixed granite, mixed gneiss, rock hard, rock integrity, rock stratum steep inclination, suitable for the construction of arch dam.
(2) Structural planes are developed in the dam area, mainly including faults, compression zones (planes), shear zones, joints and cracks. There are no I, II structural planes on the right bank, and III, IV faults are divided into three groups according to strike: SE150 degree, SW229 degree and SW252 degree. The extensional length is more than 200 m, and the average width of fracture is 0.25 M. The V-class structural plane is random fracture, the inclination angle of fracture is steep, the middle inclination angle is secondary, and the gentle inclination fracture is also developed.
(3) The weathering zones of the abutment rock mass on the right bank of Maji Hydropower Station are divided according to the code and the seismic P-wave velocity, RQD and joint spacing are introduced, and the three-dimensional fracture network simulation is carried out according to the weathering section by Monte Carlo method.
(4) Three-dimensional geological modeling of topographic surface, rock strata, dike inclusions, weathering surface, deterministic faults and simulated fissures is carried out in a ratio of 1:1000 by using three-dimensional geological modeling software, and a new method of establishing rock mass structural model by using commercial software is innovatively put forward, which has strong generalization.
(5) On the basis of the three-dimensional characterization of rock mass structure, the structural planes and bodies of rock mass structure are studied. Cracks have the regularity of developing up steeply and down slowly. The spacing of cracks on the whole shows the regularity of increasing with the increase of cave depth and elevation, and the crack trace length mostly obeys gamma distribution. It is found that the block units are mainly plate-like, strip-like, pyramid-like, prism-like and complex shapes, with the largest proportion of pyramid-like blocks, followed by plate-like and prism-like ones. And mosaic structure, the rock mass in the weak weathering zone is interbedded structure to medium-thick bedded structure, the slightly weathered rock mass is thick bedded structure or block structure, and the fresh rock mass is huge thick bedded structure or block structure. Pieces.
(6) Macroscopic rock mass structure formed by cutting fault system is studied through perspective topography. The abutment rock mass is cut into huge columns and layers by the fault, and the stability of the abutment is controlled by the cracks outside the gentle slope with the highest connectivity of 55.8%. Taking the bottom sliding surface and the side crack surface, six potential sliding blocks are searched out by using the three-dimensional structural model and expressed, which lays a foundation for the stability evaluation of the abutment in the future.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TV223;TV642.4

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本文編號(hào)：2218022