下穿隧道邊坡危巖崩塌滾石運動機理及安全防護
發(fā)布時間：2019-02-16 16:26
【摘要】：鐵路與公路隧道在西南山區(qū)的交通建設(shè)中極為常見,是交通建設(shè)的關(guān)鍵,由于山區(qū)地形條件的制約,隧道連續(xù)穿山施工現(xiàn)象較為普遍,導(dǎo)致道進出洞口地段常為地形險峻、巖體破碎、危巖出露的高陡邊坡地段,修建明洞結(jié)構(gòu)是保證交通安全的必要手段。受到巖石風化、地震、強降雨等自然因素的影響,坡頂?shù)奈r一旦垮塌,將對隧道明洞段造成直接沖擊,嚴重時將導(dǎo)致明洞結(jié)構(gòu)斷裂、垮塌,對公路及鐵路交通運輸安全造成巨大威脅。因此,充分分析邊坡滾石的運動模式、運動機理與規(guī)律,了解滾石對明洞結(jié)構(gòu)的沖擊特性,可為明洞段滾石的防護提供有力理論借鑒,具有重要研究意義。本文以西南山區(qū)鐵路隧道為依托,通過理論分析、模型試驗與數(shù)值計算等方法,研究滾石運動模式、運動機理及其對下方明洞結(jié)構(gòu)的沖擊影響,并結(jié)合工程實際進行滾石運動軌跡的模擬,為滾石防護設(shè)計提供參考依據(jù)。首先,將滾石沖擊洞口模式進行劃分,分析不同運動模式的成因,并進行沖擊能量與破壞性對比,便于根據(jù)不同滾石沖擊模式進行針對性的工程防護。其次,研制下穿隧道邊坡危巖崩塌運動機理模型試驗系統(tǒng)。根據(jù)不同滾石沖擊運動模式建立力學(xué)模型并進行理論分析,掌握滾石運動規(guī)律；進行豎直墜落型、滑移滾動型與碰撞彈跳型沖擊運動模型試驗,分析明洞結(jié)構(gòu)沖擊速度恢復(fù)系數(shù)變化規(guī)律,研究質(zhì)量與形狀的變化對滾石滑移滾動運動特性的影響,并得出不同沖擊模式對明洞結(jié)構(gòu)的沖擊破壞影響規(guī)律。再次,將試驗結(jié)果與工程實際結(jié)合,建立基于可拓法的滾石沖擊明洞風險評價模型,并對現(xiàn)場六組危巖的沖擊風險進行評定,為滾石防護提供參考。最后,根據(jù)現(xiàn)場沖擊風險性較高的三條軌跡剖面,建立數(shù)值分析模型,進行18種工況的滾石運動軌跡計算,分析滾石質(zhì)量、崩塌位置與坡面特性對滾石沖擊明洞的速度、能量與沖擊高度等參數(shù)的影響；根據(jù)計算結(jié)果進行滾石被動防護網(wǎng)的布設(shè)位置、范圍、高度與沖擊能級的設(shè)計,并驗算防護效果,結(jié)果表明,被動防護網(wǎng)的布設(shè)可有效防止?jié)L石崩塌對明洞結(jié)構(gòu)的沖擊,為降低施工風險,保證交通安全提供有力保障。
[Abstract]:Railway and highway tunnels are very common in the traffic construction of southwest mountain area, and are the key of traffic construction. Because of the restriction of terrain condition in mountainous area, the construction phenomenon of continuous tunnel passing through the mountain is relatively common, which leads to the steep terrain in the entrance and exit of the tunnel. In the high and steep slope with broken rock mass and dangerous rock, it is necessary to build a clear tunnel structure to ensure traffic safety. Affected by natural factors such as rock weathering, earthquake and heavy rainfall, once the dangerous rock at the top of the slope collapses, it will cause a direct impact on the open tunnel section of the tunnel, and when serious, it will lead to the fracture and collapse of the structure of the open tunnel. It poses a great threat to the safety of road and railway transportation. Therefore, it is of great significance to fully analyze the movement mode, motion mechanism and law of the rolling stone in slope, and to understand the impact characteristics of the rolling stone on the structure of the open tunnel, which can provide a powerful theoretical reference for the protection of the rolling stone in the section of the open tunnel. Based on the railway tunnel in southwest mountainous area, through theoretical analysis, model test and numerical calculation, this paper studies the rolling stone movement mode, motion mechanism and its impact on the structure of the lower open tunnel. Combined with the engineering practice, the rolling stone trajectory simulation is carried out, which provides a reference for the rolling stone protection design. Firstly, the rock impact hole model is divided, and the causes of different movement modes are analyzed, and the impact energy is compared with the destructive effect, which is convenient for engineering protection according to different rolling stone impact modes. Secondly, a model test system of rock collapse mechanism of underpass tunnel slope is developed. According to the different rolling stone impact movement mode, the mechanical model is established and the theoretical analysis is carried out to master the rolling stone movement law. The impact motion model tests of vertical falling, sliding rolling and impact bouncing are carried out to analyze the change rule of impact velocity recovery coefficient of open tunnel structure, and to study the influence of mass and shape on rolling motion characteristics of rolling stone. The effects of different impact modes on the impact failure of the open tunnel structure are obtained. Thirdly, combining the test results with the engineering practice, the risk assessment model of rolling rock impact open tunnel based on extension method is established, and the impact risk of six groups of dangerous rock in the field is evaluated, which provides a reference for the protection of rolling stone. Finally, according to the three trajectory profiles with high impact risk, a numerical analysis model is established to calculate the rolling stone trajectory under 18 working conditions, and to analyze the impact velocity of the rolling stone on the open hole by the mass of the rolling stone, the location of the collapse and the characteristics of the slope surface. The influence of the parameters such as energy and impact height; According to the calculation results, the location, range, height and impact energy level of the rolling stone passive protective net are designed, and the protective effect is checked. The results show that the placement of the passive protective net can effectively prevent the impact of the rolling stone collapse on the structure of the open tunnel. In order to reduce construction risks and ensure traffic safety to provide effective protection.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U458.3
本文編號：2424629
[Abstract]:Railway and highway tunnels are very common in the traffic construction of southwest mountain area, and are the key of traffic construction. Because of the restriction of terrain condition in mountainous area, the construction phenomenon of continuous tunnel passing through the mountain is relatively common, which leads to the steep terrain in the entrance and exit of the tunnel. In the high and steep slope with broken rock mass and dangerous rock, it is necessary to build a clear tunnel structure to ensure traffic safety. Affected by natural factors such as rock weathering, earthquake and heavy rainfall, once the dangerous rock at the top of the slope collapses, it will cause a direct impact on the open tunnel section of the tunnel, and when serious, it will lead to the fracture and collapse of the structure of the open tunnel. It poses a great threat to the safety of road and railway transportation. Therefore, it is of great significance to fully analyze the movement mode, motion mechanism and law of the rolling stone in slope, and to understand the impact characteristics of the rolling stone on the structure of the open tunnel, which can provide a powerful theoretical reference for the protection of the rolling stone in the section of the open tunnel. Based on the railway tunnel in southwest mountainous area, through theoretical analysis, model test and numerical calculation, this paper studies the rolling stone movement mode, motion mechanism and its impact on the structure of the lower open tunnel. Combined with the engineering practice, the rolling stone trajectory simulation is carried out, which provides a reference for the rolling stone protection design. Firstly, the rock impact hole model is divided, and the causes of different movement modes are analyzed, and the impact energy is compared with the destructive effect, which is convenient for engineering protection according to different rolling stone impact modes. Secondly, a model test system of rock collapse mechanism of underpass tunnel slope is developed. According to the different rolling stone impact movement mode, the mechanical model is established and the theoretical analysis is carried out to master the rolling stone movement law. The impact motion model tests of vertical falling, sliding rolling and impact bouncing are carried out to analyze the change rule of impact velocity recovery coefficient of open tunnel structure, and to study the influence of mass and shape on rolling motion characteristics of rolling stone. The effects of different impact modes on the impact failure of the open tunnel structure are obtained. Thirdly, combining the test results with the engineering practice, the risk assessment model of rolling rock impact open tunnel based on extension method is established, and the impact risk of six groups of dangerous rock in the field is evaluated, which provides a reference for the protection of rolling stone. Finally, according to the three trajectory profiles with high impact risk, a numerical analysis model is established to calculate the rolling stone trajectory under 18 working conditions, and to analyze the impact velocity of the rolling stone on the open hole by the mass of the rolling stone, the location of the collapse and the characteristics of the slope surface. The influence of the parameters such as energy and impact height; According to the calculation results, the location, range, height and impact energy level of the rolling stone passive protective net are designed, and the protective effect is checked. The results show that the placement of the passive protective net can effectively prevent the impact of the rolling stone collapse on the structure of the open tunnel. In order to reduce construction risks and ensure traffic safety to provide effective protection.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U458.3
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