發(fā)布時間：2018-05-05 03:17

  本文選題：香溪河 + 公路岸坡再造　； 參考：《中國地質大學》2015年博士論文

【摘要】：三峽水庫已經(jīng)歷多個蓄水階段,于2010年10月首次蓄水至175m水位。2013年開始正常運營后,庫水位每年在145m至175m之間周期性升降,水位變幅帶(消落帶)范圍高達30m。宜巴高速公路主線局部段和興山連接線(以下簡稱“研究區(qū)”)是沿香溪河庫岸設計和建設的通往興山縣和神龍架林區(qū)的旅游干線公路。香溪河庫岸段公路路面設計高程在176m～200m之間,離175m正常蓄水位很近,公路岸坡和橋基邊坡長期處于水位循環(huán)漲落(飽水-風干)的環(huán)境中。高達30m的水位變幅,加上蓄水、泄洪而頻繁發(fā)生的水位升降甚至聯(lián)合強降雨作用所構成的復雜動水條件,必將成為新一輪岸坡再造的重要營力,也將使得三峽庫區(qū)岸坡的水文、地質環(huán)境條件發(fā)生重大改變,勢必引發(fā)新的岸坡再造和庫岸滑坡災害等,嚴重威脅到了庫區(qū)的交通安全和庫區(qū)人民的生命財產(chǎn)安全。因此,對庫岸公路涉水岸坡進行再造機理研究,具有重要的理論和現(xiàn)實意義。本文在現(xiàn)場調查分析的基礎上,通過現(xiàn)場鉆孔取樣、現(xiàn)場巖體聲波測試、室內巖塊物理力學性質試驗、離心模型試驗、數(shù)值模擬分析與現(xiàn)場監(jiān)測分析等手段,對研究區(qū)岸坡巖體質量的劣化機制、土質滑坡的塌岸機理、岸坡巖體質量分級以及研究區(qū)岸坡再造類型及其穩(wěn)定性進行了分析研究,取得了以下主要成果：(1)研究區(qū)岸坡工程地質特征研究與岸坡再造類型分類①通過對研究區(qū)的綜合調查與分析,將研究區(qū)岸坡結構類型及其特征進行分段描述,并將岸坡再造類型總結為沖刷磨蝕型、坍崩滑塌型和整體滑移型三大類。②通過對研究區(qū)典型巖土體進行物理力學性質試驗,獲得了研究區(qū)岸坡巖土的物理力學參數(shù),為離心模型試驗和數(shù)值模擬計算提供了參數(shù)依據(jù)。(2)岸坡巖體(石)劣化機制試驗研究成果①通過對典型巖質岸坡進行試驗研究,試驗成果表明受庫水位升降影響粉砂巖岸坡和灰?guī)r岸坡的巖體裂隙較發(fā)育,為較破碎～破碎巖體。②通過對巖石干濕循環(huán)試驗試樣進行單軸抗壓強度劣化試驗,成果表明粉砂巖和灰?guī)r強度劣化程度隨干濕循環(huán)次數(shù)增加呈增長發(fā)展趨勢；相同條件下,粉砂巖的劣化速率明顯高于灰?guī)r,說明庫水對軟巖的影響作用更加明顯。③通過耐崩解性試驗,成果表明巖石的耐崩解性指數(shù)(Id)隨崩解循環(huán)次數(shù)(N)的增加而減小,且兩者存在對數(shù)函數(shù)關系,即Id=a×Ln(N)+b,式中a和b為與巖性有關的系數(shù)。針對粉砂巖,還發(fā)現(xiàn)系數(shù)a和b還與試樣取自的高程有關,高程越高的巖塊越容易風化崩解,同時a和b表現(xiàn)為降低。(3)庫水升降作用下岸坡巖體質量分級研究成果①針對現(xiàn)有方法的不足,考慮到三峽庫區(qū)周期性升降的規(guī)律性,引入了岸坡“巖體質量總劣化度”Dh(n)和“巖體質量年度劣化度”d (h)兩個指標,對涉水岸坡巖體進行巖體質量分級評價,建立了岸坡巖體質量分級評價預測公式：[BQ]h(n)=(1-nd(h))[BQ]h(o)。②依據(jù)BQ法對庫區(qū)兩個典型岸坡進行了巖體質量分級應用與評價,并對粉砂巖L岸坡不同高程段巖體質量進行預測,提出了巖體質量預測公式,即：上述公式表明岸坡巖體質量[BQ]與高程h和水庫運行年數(shù)n有關。(4)公路庫岸塌岸機理離心模型試驗研究成果采用離心模型試驗,研究了水位驟降和降雨耦合水位驟降兩種工況下庫岸滑坡“啟動-發(fā)展-破壞”過程的塌岸機理。模型試驗成果表明：水位驟降是導致公路庫岸滑坡的最主要影響因素之一。水位驟降發(fā)生的瞬間,岸坡沿深部軟弱面產(chǎn)生了整體滑動,隨后滑動位移逐級增大；同時,位于原水位線附件的岸坡立刻產(chǎn)生細小裂紋,而原水位線以下坡面上的裂紋隨后逐級出現(xiàn)并向兩端擴展延伸,受前部滑塌牽引影響后部裂縫也逐漸擴大�？讐罕O(jiān)測值的突變分析表明,裂紋逐級還存在向邊坡內部延伸。降雨過程降低了邊坡土層的抗剪強度,使邊坡產(chǎn)生了少量的位移,但未影響邊坡的整體穩(wěn)定性。試驗研究表明,兩組工況下涉水岸坡均發(fā)生了整體性滑動,并且滑動面均沿著深部的軟弱層發(fā)生發(fā)展。(5)研究區(qū)岸坡穩(wěn)定性分析成果①研究區(qū)典型滑坡在不同降水條件下的穩(wěn)定性特征,分析認為：妃臺山滑坡模擬研究成果表明,在庫水以0.6m/d和1.2m/d下降2種工況下,滑坡穩(wěn)定系數(shù)都大于1,表明目前滑坡體是穩(wěn)定的。但庫水位下降速度對滑坡的穩(wěn)定性影響明顯,下降速度越快,滑坡越不穩(wěn)定。周家坡滑坡模擬研究成果表明,在庫水以及2.0m/d三種模式下降時,滑0.6m/d、1.2m/d坡穩(wěn)定系數(shù)均有明顯下降,穩(wěn)定系數(shù)的降低速率和幅度和庫水位下降速率關系密切,庫水位驟降對庫岸滑坡的穩(wěn)定性極為不利,庫水位快速下降(驟降)是庫岸潛在滑坡體和古(老)滑坡復活的主要誘因之一。同時,在庫水位下降到145m后穩(wěn)定的一段時間內,三種模式下的滑坡穩(wěn)定系數(shù)達到最低后均有少量的提高(反彈)。②基于對公路建設中典型邊(滑)坡體的深部變形監(jiān)測成果的分析評價,認為堆積體滑坡的變形發(fā)生發(fā)展主要是受工程施工聯(lián)合降雨尤其是較強降雨綜合作用影響的結果。公路建設過程中挖方、堆載、施工放炮、機械車輛的頻繁碾壓改變了坡體外形,打破了坡體的初始應力平衡狀態(tài),而降雨及地表水入滲弱化了坡體物質的抗剪強度,增加了坡體的重量,加速了邊坡變形,從而導致滑坡的產(chǎn)生,這也是工程滑坡多發(fā)生在雨季的原因。③綜合上述研究成果,充分考慮岸坡基本因素和影響因素聯(lián)合作用影響,采用動態(tài)權重模糊評價體系,對研究區(qū)岸坡穩(wěn)定性進行了定性分類評價,將研究區(qū)公路岸坡穩(wěn)定性劃分為穩(wěn)定、基本穩(wěn)定、次不穩(wěn)定和不穩(wěn)定四大類。
[Abstract]:The Three Gorges reservoir has experienced a number of water storage stages. After the first storage of water to 175m water level in October 2010, the reservoir water level fluctuated periodically from 145m to 175m each year. The range of the water level variation zone (the falling zone) was higher than that of the local section of the main line of the 30m. yicba highway and the Xingshan connection line (hereinafter referred to as the "study area") along the Xiangxi River. The design and construction of the bank bank to the Xingshan county and the Shenlong stand of the tourist trunk road. The highway pavement design elevation of the Xiangxi River bank section is between 176m and 200m, which is close to the normal storage space of the 175m. The highway bank slope and the bridge foundation slope are in the environment of the water level circulation fluctuation (full water air drying) for a long time. The level of the water level of up to 30m, plus the water storage, is added to the water. The frequent water level of flood and even the complex dynamic water conditions formed by combined heavy rainfall will certainly become an important force for a new round of bank slope reengineering. It will also make a great change in the hydrology and geological conditions of the bank slope in the Three Gorges Reservoir area, which will inevitably lead to the new bank slope reengineering and the landslide disaster of the bank bank, which seriously threatens the reservoir area. Traffic safety and the life and property of the people in the reservoir area are safe. Therefore, it is of great theoretical and practical significance to study the reengineering mechanism of the bank slope of the bank highway. On the basis of the field investigation and analysis, this paper through the field drilling sampling, the field rock sound wave test, the indoor rock mass physical and mechanical properties test, the centrifugal model test, the numerical value. By means of simulation analysis and field monitoring and analysis, the deterioration mechanism of rock mass quality in the bank slope, the mechanism of landslides, the quality classification of slope rock mass and the type and stability of the bank slope reengineering in the study area are analyzed and studied. The following main achievements have been obtained: (1) the research on the engineering geological characteristics of the bank slope and the reengineering of the bank slope in the study area Type classification (1) by comprehensive investigation and analysis of the study area, the type and characteristics of the bank slope structure in the study area are segmented, and the types of bank slope reengineering are summarized into three categories: erosion and erosion type, collapse type and holistic slip type. The physical and mechanical parameters of the slope rock provide parameter basis for the centrifugal model test and numerical simulation. (2) the experimental research results of the deterioration mechanism of the rock mass (stone) of the bank slope are tested by the experimental study on the typical rock slope. The results show that the reservoir water level rise and fall affect the rock fracture of the silt slope and the limestone bank slope. The results show that the deterioration degree of the strength of the siltstone and limestone increases with the increase of dry and wet cycle times, and the deterioration rate of the siltstone is higher than that of the limestone under the same condition, indicating that the influence of the reservoir water to the soft rock is more important. Through the disintegration test, the results show that the rock collapse resistance index (Id) decreases with the increase of the number of disintegration cycles (N), and there is a logarithmic function relationship between them, that is, Id=a * Ln (N) +b, a and B are related to lithology in the form of the siltstone, and the coefficient a and B are also related to the elevation of the sample, and the higher the elevation The rock mass is easier to be weathered and disintegrate, and the performance of a and B is reduced. (3) study on the quality classification of rock mass in the bank slope under the action of reservoir water fluctuation (1), in view of the shortcomings of the existing methods, considering the regularity of the periodic rise and fall of the Three Gorges Reservoir area, two indexes of the "total degradation degree of rock mass" Dh (n) and the "annual deterioration degree of rock mass" (d (H)) are introduced. According to the evaluation of rock mass quality classification, the prediction formula of rock mass quality classification is established: [BQ]h (n) = (1-nd (H)) [BQ]h (o). (2) the rock mass quality classification of two typical bank slopes in the reservoir area is applied and evaluated according to BQ method, and the rock mass quality of the siltstone L bank slope at different elevation is predicted, and the rock constitution is put forward. The formula of quantity prediction, that is, the above formula shows that the mass [BQ] of the bank slope is related to the height of the elevation h and the year number of the operation of the reservoir. (4) the centrifugal model test of the bank bank collapse mechanism of the bank bank is carried out by centrifugal model test, and the bank bank landslide "start development failure" of the bank slope under the water level drop and the sudden drop of the rainfall coupling water level are studied. The result of the model test shows that the sudden drop of water level is one of the most important factors that lead to the landslide of the highway bank. At the moment of the sudden drop of the water level, the bank slope has a whole sliding along the deep soft surface, and then the sliding displacement increases step by step. At the same time, the bank slope at the original water level line appendix produces small cracks, and the original water level is below the water level line. The cracks on the sloping surface then appear step by step and extend to the two ends, and the cracks in the rear part are gradually expanded by the sliding traction of the front part. The abrupt analysis of the monitoring value of the pore pressure indicates that the crack is also extended to the side of the slope. The rainfall process reduces the shear strength of the slope soil and causes the slope to produce a small amount of displacement, but does not affect the slope. The experimental study shows that the slope of the water wading slope in the two groups is all sliding, and the sliding surface is developed along the deep weak layer. (5) the stability analysis of the bank slope in the study area (1) the characteristics of the stability of the typical landslides in the study area under different precipitation conditions, the analysis is that the simulation of the imperial concubine Taishan landslide The results show that the landslide stability coefficient is more than 1 under the 2 conditions of 0.6m/d and 1.2m/d decline, which indicates that the landslide body is stable at present. But the decline velocity of the reservoir water level has an obvious effect on the stability of the landslide, the faster the decline speed is, the more unstable the landslide is, the results of the Zhou Jiapo landslide simulation study show that when the three modes of reservoir water and 2.0m/d fall, The slope stability coefficient of sliding 0.6m/d, 1.2m/d slope stability coefficient decreased obviously, the decrease rate and amplitude of stability coefficient are closely related to the decline rate of reservoir water level. The sudden drop of reservoir water level is extremely unfavorable to the stability of bank slope, and the rapid decline of reservoir water level (sudden drop) is one of the main causes of the resurrection of potential landslides and old landslides in the bank bank. In a stable period after falling to 145m, the landslide stability coefficient in the three modes reached a minimum and a little increase (rebound). Secondly, based on the analysis and evaluation of the monitoring results of the deep deformation of the typical side (slippery) slope in the highway construction, the development and development of the landslide is mainly due to the joint rainfall of the construction and especially the comparison. The result of the influence of the comprehensive effect of heavy rainfall. In the course of highway construction, excavating, loading, construction and blasting, the frequent rolling of mechanical vehicles changed the shape of the slope body, broken the initial stress balance state of the slope, and the rainfall and surface water infiltration weakened the shear strength of the slope body material, increased the weight of the slope body, accelerated the slope deformation, thus guided the slope deformation. Thus, the slope deformation was accelerated, thus guiding the slope deformation and thus guiding the slope. This is also the cause of the landslide, which is also the cause of the landslide occurring in the rainy season. 3. Comprehensive analysis of the above results, fully considering the impact of the basic factors and factors of the impact of the bank slope, using the dynamic weight fuzzy evaluation system, the stability of the bank slope in the study area is qualitatively classified and evaluated, and the stability of the bank slope in the study area is divided into stability. Fixed, basically stable, sub unstable and unstable four main categories.

【學位授予單位】：中國地質大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：U416.1;TV223
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本文編號：1845947