本文選題：圍巖自穩(wěn)能力 + 強(qiáng)度折減法　； 參考：《湖南大學(xué)》2015年碩士論文

【摘要】：現(xiàn)代地下結(jié)構(gòu)支護(hù)原理認(rèn)為圍巖既是產(chǎn)生山巖壓力的來源,更是承載的主體,人工支護(hù)起輔助承載作用。但據(jù)此發(fā)展而來的行業(yè)規(guī)范僅給出各級圍巖支護(hù)的定性描述,其具體支護(hù)類型及參數(shù)則依賴決策人員的工程經(jīng)驗類比確定,造成了材料的不必要浪費。因此,為使支護(hù)設(shè)計向定量化方向發(fā)展,本文以圍巖自穩(wěn)能力為研究對象,開展了如下幾方面的研究:首先,論述強(qiáng)度折減數(shù)值分析方法在巖土工程穩(wěn)定性計算中的應(yīng)用,并對有限差分軟件FLAC的工作原理及其優(yōu)缺點做簡要介紹,繼而借助增量彈性理論和既定流動法則對剪破壞和拉破壞情況下的M-C塑性應(yīng)力修正值做差分形式推導(dǎo)。然后,引入運(yùn)動平衡的概念將圍巖自穩(wěn)狀態(tài)劃分為穩(wěn)定平衡狀態(tài)和非穩(wěn)定平衡狀態(tài)兩種,同時提出以塑性區(qū)和關(guān)鍵點位移變化特征為據(jù),分段擬合圍巖彈塑性變形和塑性流動階段曲線方程,聯(lián)立求解以鎖定圍巖臨界破壞特征點的方法。之后,依托大量規(guī)范辨識出圍巖強(qiáng)度恰能承受住所有破壞力作用的極限狀態(tài),并運(yùn)用FLAC3D和強(qiáng)度折減思想求此狀態(tài)下圍巖穩(wěn)定系數(shù)k0,以k0作為恒穩(wěn)判別的定量標(biāo)準(zhǔn),然后通過大量數(shù)值模擬辨識出II~IV級圍巖保持長久穩(wěn)定的條件,初步量化了其圍巖自承載結(jié)構(gòu)在維持硐室穩(wěn)定中所起作用。再有,先對滿足隧洞工程建筑內(nèi)限要求的等面積四大斷面形式做穩(wěn)定性計算,對k0進(jìn)行修正;再采用不同泊松比和彈性模量對某隧洞圍巖進(jìn)行強(qiáng)度弱化模擬,發(fā)現(xiàn)泊松比和彈模對穩(wěn)定系數(shù)影響極小,進(jìn)而克服了傳統(tǒng)塑性區(qū)判據(jù)和位移判據(jù)因此二者測量不準(zhǔn)而判定不一的缺陷;緊接著開展室內(nèi)相似模型試驗,所得結(jié)果與數(shù)值模擬結(jié)果相互印證,從而驗證恒穩(wěn)系數(shù)k0的正確性。其次,分析不同支護(hù)類型的力學(xué)特性和作用機(jī)理,并結(jié)合勘察資料和公路隧道設(shè)計規(guī)范,運(yùn)用本文方法給出廣西蒙沙隧道(1)標(biāo)段III級圍巖的支護(hù)優(yōu)化方案。最后,針對現(xiàn)有錨桿延伸率低、不能適應(yīng)巷道圍巖大變形需要的問題,發(fā)明設(shè)計了一種新型增阻讓壓構(gòu)件,并開展了相關(guān)工作。
[Abstract]:The principle of modern underground structure support holds that the surrounding rock is not only the source of mountain rock pressure, but also the main body of bearing capacity, and artificial support plays an auxiliary role in carrying capacity. But the industry standard developed according to this only gives the qualitative description of surrounding rock support at all levels, and its concrete support types and parameters depend on the engineering experience analogy of the decision makers, resulting in unnecessary waste of materials. Therefore, in order to make the support design develop to the quantitative direction, this paper takes the self-stability ability of surrounding rock as the research object, carries out the following research: first, discusses the application of the strength reduction numerical analysis method in the geotechnical engineering stability calculation. The working principle, advantages and disadvantages of finite difference software FLAC are briefly introduced, and then the modified values of M-C plastic stress under shear failure and tensile failure are derived by means of incremental elasticity theory and established flow rule. Then, the concept of motion equilibrium is introduced to divide the self-stability state of surrounding rock into two kinds: stable equilibrium state and non-stable equilibrium state. At the same time, the characteristics of displacement change in plastic zone and key point are proposed as the basis. The phase curve equation of elastoplastic deformation and plastic flow of surrounding rock is fitted in sections, and the method of locking the critical failure characteristic point of surrounding rock is solved simultaneously. After that, based on a large number of codes, the strength of surrounding rock can be identified as the limit state of the destructive effect of residence, and the stability coefficient of surrounding rock under this condition is obtained by using FLAC3D and strength reduction thought, and K0 is taken as the quantitative criterion for the determination of constant stability. Then, the conditions for the II~IV class rock to maintain long-term stability are identified by a large number of numerical simulations, and the role of the surrounding rock self-bearing structure in maintaining the stability of the chamber is preliminarily quantified. Secondly, the stability of four sections with equal area to meet the requirements of the inner limit of tunnel construction is calculated, and k0 is modified, and then the strength of surrounding rock of a tunnel is simulated by using different Poisson's ratio and elastic modulus. It is found that Poisson's ratio and modulus of elasticity have minimal influence on the stability coefficient, which overcomes the defects of traditional plastic zone criterion and displacement criterion. The results obtained are consistent with those of the numerical simulation, which verifies the correctness of the constant stability coefficient k _ 0. Secondly, the mechanical characteristics and action mechanism of different supporting types are analyzed. Combined with the survey data and the design code of highway tunnel, the support optimization scheme of III grade surrounding rock in the section of Mengsha tunnel in Guangxi is given by using the method of this paper. Finally, in order to solve the problem of low elongation of existing bolt, which can not adapt to the need of large deformation of surrounding rock of roadway, a new type of resistance and pressure increasing component is designed and related work is carried out.
【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU45

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張騰;胡斌;王偉;饒晨曦;;基于Phase2的強(qiáng)度折減法土質(zhì)邊坡穩(wěn)定性研究[J];人民黃河;2014年03期

2 劉強(qiáng);胡斌;蔣海飛;王新剛;郭利娜;;基于強(qiáng)度折減法的露采邊坡穩(wěn)定性分析[J];金屬礦山;2013年05期

3 孔不凡;阮懷寧;朱珍德;袁文軍;陳振振;;邊坡穩(wěn)定的離散元強(qiáng)度折減法分析[J];人民黃河;2013年04期

4 曹茂柏;;對混凝土彈性模量影響因素的探討[J];科技通報;2012年12期

5 張智慧;王學(xué)濱;潘一山;;利用多種相似材料模擬分區(qū)破裂現(xiàn)象的試驗研究[J];水資源與水工程學(xué)報;2011年03期

6 蘇永華;李翔;徐能雄;羅正東;;錨噴襯砌隧道結(jié)構(gòu)穩(wěn)定可靠度計算[J];土木工程學(xué)報;2011年03期

7 楊光華;鐘志輝;張玉成;李德吉;;用局部強(qiáng)度折減法進(jìn)行邊坡穩(wěn)定性分析[J];巖土力學(xué);2010年S2期

8 周洪波;付成華;;地下工程圍巖穩(wěn)定性分析方法及失穩(wěn)判據(jù)評述與展望[J];四川水力發(fā)電;2008年S3期

9 賈蓬;唐春安;楊天鴻;李連崇;;強(qiáng)度折減法在巖石隧道穩(wěn)定性研究中的應(yīng)用[J];力學(xué)與實踐;2007年03期

10 李蒼松;高波;王石春;;巖溶圍巖分級初步探討[J];工程地質(zhì)學(xué)報;2006年06期

相關(guān)碩士學(xué)位論文 前1條

1 祁洪;大跨度隧道圍巖穩(wěn)定性分析[D];中國地質(zhì)大學(xué)（北京）;2007年

，

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