金沙江上游蘇洼龍滑坡形成機制與穩(wěn)定性研究
發(fā)布時間：2018-08-02 14:08
【摘要】：蘇洼龍滑坡位于金沙江上游巴塘-中咱一帶,地處構(gòu)造活動十分強烈的青藏高原東南緣的高山峽谷區(qū),地震活動頻繁且強度大,地質(zhì)環(huán)境相當復(fù)雜。研究區(qū)內(nèi)沿金沙江河谷發(fā)育有大量古滑坡,對古滑坡的形成機制、穩(wěn)定性及其發(fā)展趨勢進行研究,為本地區(qū)重大工程的規(guī)劃選址提供科學(xué)依據(jù)。本文以金沙江上游蘇洼龍滑坡為例,根據(jù)野外地質(zhì)調(diào)查、實地測量,結(jié)合室內(nèi)實驗及前人研究成果,對蘇洼龍滑坡及其周邊湖相沉積物的空間分布和形成年代、滑坡的成因機制以及破壞特征進行了初步的研究；然后基于FLAC3D軟件運用數(shù)值模擬分析手段對蘇洼龍滑坡殘留堆積體在自然工況、暴雨工況和地震工況等三種工況下的穩(wěn)定性做出了評價,得出以下結(jié)論：(1)蘇洼龍滑坡為大型巖質(zhì)古滑坡,滑坡發(fā)生后即堰塞金沙江并到達對岸,形成了堰塞湖。利用’4C測年和光釋光(OSL)測年方法確定了蘇洼龍古滑坡及其周圍一帶堰塞湖湖相沉積物的形成年代,結(jié)果表明：蘇洼龍滑坡堵江事件發(fā)生的時間是在1355 BP左右,其周邊發(fā)育的兩級湖相沉積物平臺形成的時代分別為1.8 ka BP和1.3 ka BP。(2)堰塞湖湖相沉積物中發(fā)現(xiàn)的兩種軟沉積物變形(液化卷曲構(gòu)造和球枕構(gòu)造),揭示了該區(qū)在1115BP左右,至少發(fā)生了一次震級不小于5級的古地震；推測導(dǎo)致蘇洼龍滑坡發(fā)生的原因可能是地震或者是地震和降雨的聯(lián)合作用。(3)蘇洼龍滑坡壩的湖相沉積特征及年代學(xué)表明了金沙江上游王大龍大型滑坡群具有多期次的特點,即它們可能是多次古地震誘發(fā)形成的。自1900 BP以來,該區(qū)受雄松-蘇洼龍活動斷裂的影響,曾發(fā)生過至少多次古地震(1900 BP, 1355 BP,1115 BP),表明該區(qū)活動斷裂自全新世晚期以來一直是十分活躍的。(4)強烈的地質(zhì)動力作用和存在有利結(jié)構(gòu)面是蘇洼龍滑坡形成的重要條件。推測滑坡變形破壞過程如下：后緣形成拉裂縫—震裂裂縫加深和拉長—坡體前緣剪切破壞—山體震裂松動—滑面形成—快速滑動—堰塞金沙江。(5)基于FLAC3D軟件,對滑坡的穩(wěn)定性進行模擬計算,結(jié)果顯示滑坡在自然工況和暴雨工況下是穩(wěn)定的,但在本文給定的地震動力作用下發(fā)生失穩(wěn)破壞。
[Abstract]:The Suwulong landslide is located in the upper reaches of the Jinsha River from Batang-Zhongzan. It is located in the alpine canyon area of the southeast margin of the Qinghai-Tibet Plateau, where the tectonic activity is very strong. The seismic activity is frequent and the intensity is high, and the geological environment is quite complex. There are a large number of ancient landslides developed along the Jinsha River valley in the study area. The formation mechanism, stability and development trend of the ancient landslides are studied, which provides scientific basis for the planning and location selection of the major projects in this area. Taking the Suwulong landslide in the upper reaches of Jinsha River as an example, according to the field geological survey, field survey, laboratory experiments and previous research results, the spatial distribution and formation age of the Suwulong landslide and its surrounding lacustrine sediments are studied. The cause mechanism and failure characteristics of landslide are studied preliminarily, and then the residual accumulation of landslide in Suwulong is analyzed by numerical simulation based on FLAC3D software. The stability of the landslide is evaluated under the conditions of rainstorm and earthquake, and the following conclusions are drawn: (1) Suwulong landslide is a large ancient rock landslide. After the landslide occurs, the Weir River reaches the opposite bank and forms a barrier lake. The formation age of the sediments of the ancient landslide in Suwulong and its surrounding areas of the barrier lake is determined by using the dating method of Yao4C and (OSL). The results show that the time of the event of blocking the river in the landslide of Suwulong is about 1355 BP. The formation times of the two-stage lacustrine sediment platform are 1.8 ka BP and 1.3 ka BP. (2, respectively. Two types of soft sediment deformation (liquefaction convoluted structure and ball pillow structure) found in the lake sediments revealed that the area is around 1115BP. At least one paleo-earthquake of magnitude not less than 5 occurred; It is speculated that the occurrence of Suwulong landslide may be caused by earthquake or the combined action of earthquake and rainfall. (3) the lacustrine sedimentary characteristics and chronology of Suwulong landslide dam indicate that the large landslide group of Wang Dalong in the upper reaches of Jinsha River has the characteristics of multiple periods. That is, they may have been induced by multiple paleoearthquakes. Since 1900 BP, the area has been affected by the Xiongsong-Suwulong active fault. At least a number of paleoearthquakes (1900 BP, 1355 BP ~ 1115 BP),) have shown that the active faults in this area have been active since the late Holocene. (4) strong geodynamic action and the existence of favorable structural surface are the important conditions for the formation of Suhualong landslide. It is inferred that the process of deformation and failure of landslide is as follows: the forming of tension fissure, the deepening of seismic crack and the elongated shear failure of front edge of slope body, the formation of earthquake crack loosening of mountain body, the formation of sliding surface, the rapid sliding of Weir plug Jinshajiang River. (5) based on FLAC3D software, The stability of the landslide is simulated and calculated. The results show that the landslide is stable under the natural condition and the rainstorm condition, but the instability and failure occur under the earthquake dynamic action given in this paper.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P642.22
本文編號：2159683
[Abstract]:The Suwulong landslide is located in the upper reaches of the Jinsha River from Batang-Zhongzan. It is located in the alpine canyon area of the southeast margin of the Qinghai-Tibet Plateau, where the tectonic activity is very strong. The seismic activity is frequent and the intensity is high, and the geological environment is quite complex. There are a large number of ancient landslides developed along the Jinsha River valley in the study area. The formation mechanism, stability and development trend of the ancient landslides are studied, which provides scientific basis for the planning and location selection of the major projects in this area. Taking the Suwulong landslide in the upper reaches of Jinsha River as an example, according to the field geological survey, field survey, laboratory experiments and previous research results, the spatial distribution and formation age of the Suwulong landslide and its surrounding lacustrine sediments are studied. The cause mechanism and failure characteristics of landslide are studied preliminarily, and then the residual accumulation of landslide in Suwulong is analyzed by numerical simulation based on FLAC3D software. The stability of the landslide is evaluated under the conditions of rainstorm and earthquake, and the following conclusions are drawn: (1) Suwulong landslide is a large ancient rock landslide. After the landslide occurs, the Weir River reaches the opposite bank and forms a barrier lake. The formation age of the sediments of the ancient landslide in Suwulong and its surrounding areas of the barrier lake is determined by using the dating method of Yao4C and (OSL). The results show that the time of the event of blocking the river in the landslide of Suwulong is about 1355 BP. The formation times of the two-stage lacustrine sediment platform are 1.8 ka BP and 1.3 ka BP. (2, respectively. Two types of soft sediment deformation (liquefaction convoluted structure and ball pillow structure) found in the lake sediments revealed that the area is around 1115BP. At least one paleo-earthquake of magnitude not less than 5 occurred; It is speculated that the occurrence of Suwulong landslide may be caused by earthquake or the combined action of earthquake and rainfall. (3) the lacustrine sedimentary characteristics and chronology of Suwulong landslide dam indicate that the large landslide group of Wang Dalong in the upper reaches of Jinsha River has the characteristics of multiple periods. That is, they may have been induced by multiple paleoearthquakes. Since 1900 BP, the area has been affected by the Xiongsong-Suwulong active fault. At least a number of paleoearthquakes (1900 BP, 1355 BP ~ 1115 BP),) have shown that the active faults in this area have been active since the late Holocene. (4) strong geodynamic action and the existence of favorable structural surface are the important conditions for the formation of Suhualong landslide. It is inferred that the process of deformation and failure of landslide is as follows: the forming of tension fissure, the deepening of seismic crack and the elongated shear failure of front edge of slope body, the formation of earthquake crack loosening of mountain body, the formation of sliding surface, the rapid sliding of Weir plug Jinshajiang River. (5) based on FLAC3D software, The stability of the landslide is simulated and calculated. The results show that the landslide is stable under the natural condition and the rainstorm condition, but the instability and failure occur under the earthquake dynamic action given in this paper.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P642.22
【參考文獻】
相關(guān)期刊論文 前5條
1 晏同珍;滑坡構(gòu)造力學(xué)某些特征分析[J];地球科學(xué);1981年02期
2 喬秀夫;李海兵;;枕、球—枕構(gòu)造:地層中的古地震記錄[J];地質(zhì)論評;2008年06期
3 伍先國,蔡長星;金沙江斷裂帶新活動和巴塘6.5級地震震中的確定[J];地震研究;1992年04期
4 黃朝光,彭大文;人工合成地震波的研究[J];福州大學(xué)學(xué)報(自然科學(xué)版);1996年04期
5 陳杰,盧演儔,尹功明,劉愛國,胡碧茹;甘肅玉門地區(qū)第四紀晚期構(gòu)造階地的紅外釋光測年[J];高校地質(zhì)學(xué)報;1996年04期
，本文編號：2159683
本文鏈接：http://sikaile.net/kejilunwen/diqiudizhi/2159683.html
最近更新
教材專著
