岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
8期
2165-2173
,共9页
隧道%围岩%变形机制%尺寸效应
隧道%圍巖%變形機製%呎吋效應
수도%위암%변형궤제%척촌효응
tunnels%surrounding rock%deformation mechanism%size effect
通过分析不同结构围岩的变形机制研究隧道变形的尺寸效应,研究结果表明隧道围岩变形的尺寸效应与围岩的变形机制存在密切的关系。围岩中由于结构面的存在使围岩的变形机制复杂多样,主要包括材料变形和结构变形两大类,围岩变形的尺寸效应也主要体现在材料变形和结构变形两方面。围岩材料变形包括弹性变形和塑性变形,均与围岩断面尺寸呈线性比例关系;围岩结构变形的尺寸效应表现为:(1)围岩结构类型随隧道断面尺寸的增大而发生改变,不同类型的围岩其变形机制不同,不同变形机制产生的围岩变形量相差较大;(2)在同一种围岩结构下,相同变形机制产生的围岩变形量也会随着隧道尺寸增大而呈现不同的变化规律,如在块状围岩中,隧道周边不可动块体会随着隧道断面尺寸的增大而转化成可动块体,从而发生滑动或者滚动变形,甚至坍塌;在层状围岩中,岩层的弯曲变形与隧道断面尺寸的平方成正比。
通過分析不同結構圍巖的變形機製研究隧道變形的呎吋效應,研究結果錶明隧道圍巖變形的呎吋效應與圍巖的變形機製存在密切的關繫。圍巖中由于結構麵的存在使圍巖的變形機製複雜多樣,主要包括材料變形和結構變形兩大類,圍巖變形的呎吋效應也主要體現在材料變形和結構變形兩方麵。圍巖材料變形包括彈性變形和塑性變形,均與圍巖斷麵呎吋呈線性比例關繫;圍巖結構變形的呎吋效應錶現為:(1)圍巖結構類型隨隧道斷麵呎吋的增大而髮生改變,不同類型的圍巖其變形機製不同,不同變形機製產生的圍巖變形量相差較大;(2)在同一種圍巖結構下,相同變形機製產生的圍巖變形量也會隨著隧道呎吋增大而呈現不同的變化規律,如在塊狀圍巖中,隧道週邊不可動塊體會隨著隧道斷麵呎吋的增大而轉化成可動塊體,從而髮生滑動或者滾動變形,甚至坍塌;在層狀圍巖中,巖層的彎麯變形與隧道斷麵呎吋的平方成正比。
통과분석불동결구위암적변형궤제연구수도변형적척촌효응,연구결과표명수도위암변형적척촌효응여위암적변형궤제존재밀절적관계。위암중유우결구면적존재사위암적변형궤제복잡다양,주요포괄재료변형화결구변형량대류,위암변형적척촌효응야주요체현재재료변형화결구변형량방면。위암재료변형포괄탄성변형화소성변형,균여위암단면척촌정선성비례관계;위암결구변형적척촌효응표현위:(1)위암결구류형수수도단면척촌적증대이발생개변,불동류형적위암기변형궤제불동,불동변형궤제산생적위암변형량상차교대;(2)재동일충위암결구하,상동변형궤제산생적위암변형량야회수착수도척촌증대이정현불동적변화규률,여재괴상위암중,수도주변불가동괴체회수착수도단면척촌적증대이전화성가동괴체,종이발생활동혹자곤동변형,심지담탑;재층상위암중,암층적만곡변형여수도단면척촌적평방성정비。
Size effect of tunnel deformation has been studied in this paper based on the deformation mechanism of different structures of rock mass. Size effect on deformation of rock mass surrounding tunnels closely relates to deformation mechanism of rock mass. Deformation mechanism of surrounding rock, which is intricate and diverse because of structural planes in the rock, includes material deformation and structural deformation. Size effect of deformation also reflects in the material deformation and structural deformation. Material deformation of surrounding rock varies directly as cross-section dimension of tunnels. Size effect of structural deformation is much more intricate. On the one hand, cross-section dimension of tunnels affects structure type of surrounding rock which closely relates to deformation mechanism; while amount of deformation provoked by different deformation mechanisms varies a great deal. On the other hand, in a same surrounding rock, amount of deformation provoked by an identical deformation mechanism also varies with size of tunnels. In the massive surrounding rock, for example, immobile rock surrounding tunnels will convert into movable rock in company with increase of cross section dimension of tunnels, and sliding or rolling deformation occurs sequentially. In the layered surrounding rock, bending deformation of rock stratification varies directly as the square of cross-section dimension of tunnels.