岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2010年
2期
242-250
,共9页
许强%范宣梅%李园%张帅
許彊%範宣梅%李園%張帥
허강%범선매%리완%장수
边坡工程%板梁状滑坡%平推式滑坡%近水平岩层滑坡%形成条件%成因机制
邊坡工程%闆樑狀滑坡%平推式滑坡%近水平巖層滑坡%形成條件%成因機製
변파공정%판량상활파%평추식활파%근수평암층활파%형성조건%성인궤제
slope engineering%plate landslide%translational landslide%landslide in flat rock bed%formation condition%genetic mechanism
以发生于四川省南江县兴马中学滑坡和大河中学滑坡这2个新老滑坡为典型案例,通过详细调查和分析解剖,提出一种新的平推式滑坡类型--板梁状滑坡.板梁状滑坡平面上呈扁长矩形,纵向长度远小于横向宽,剖面上呈薄板状.其主要发生于由近水平巨厚层砂岩和薄层泥岩构成的斜坡陡崖附近,坡内存在一组平行于坡面的长大陡倾结构面.在强降雨条件下,平行于坡面的张裂缝被快速充水至某一临界高度后,强大的静水压力将外侧岩体整体平推出去,形成平推式滑坡,而后随着裂缝内水头的骤降,滑体很快会自行止动.在较系统地研究并查明形成板梁状滑坡必须具备的岩性条件、坡体结构条件、裂缝储水条件以及强降雨触发条件的基础上,针对板梁状滑坡的后续变形破坏模式,提出加强截排水,消除在裂缝内形成高水头的条件;在板梁外侧根部采取短桩或抗滑键阻止板梁进一步向外滑动;顶部采用连梁或锚索约束其倾倒变形等有针对性的工程治理措施.
以髮生于四川省南江縣興馬中學滑坡和大河中學滑坡這2箇新老滑坡為典型案例,通過詳細調查和分析解剖,提齣一種新的平推式滑坡類型--闆樑狀滑坡.闆樑狀滑坡平麵上呈扁長矩形,縱嚮長度遠小于橫嚮寬,剖麵上呈薄闆狀.其主要髮生于由近水平巨厚層砂巖和薄層泥巖構成的斜坡陡崖附近,坡內存在一組平行于坡麵的長大陡傾結構麵.在彊降雨條件下,平行于坡麵的張裂縫被快速充水至某一臨界高度後,彊大的靜水壓力將外側巖體整體平推齣去,形成平推式滑坡,而後隨著裂縫內水頭的驟降,滑體很快會自行止動.在較繫統地研究併查明形成闆樑狀滑坡必鬚具備的巖性條件、坡體結構條件、裂縫儲水條件以及彊降雨觸髮條件的基礎上,針對闆樑狀滑坡的後續變形破壞模式,提齣加彊截排水,消除在裂縫內形成高水頭的條件;在闆樑外側根部採取短樁或抗滑鍵阻止闆樑進一步嚮外滑動;頂部採用連樑或錨索約束其傾倒變形等有針對性的工程治理措施.
이발생우사천성남강현흥마중학활파화대하중학활파저2개신로활파위전형안례,통과상세조사화분석해부,제출일충신적평추식활파류형--판량상활파.판량상활파평면상정편장구형,종향장도원소우횡향관,부면상정박판상.기주요발생우유근수평거후층사암화박층니암구성적사파두애부근,파내존재일조평행우파면적장대두경결구면.재강강우조건하,평행우파면적장렬봉피쾌속충수지모일림계고도후,강대적정수압력장외측암체정체평추출거,형성평추식활파,이후수착렬봉내수두적취강,활체흔쾌회자행지동.재교계통지연구병사명형성판량상활파필수구비적암성조건、파체결구조건、렬봉저수조건이급강강우촉발조건적기출상,침대판량상활파적후속변형파배모식,제출가강절배수,소제재렬봉내형성고수두적조건;재판량외측근부채취단장혹항활건조지판량진일보향외활동;정부채용련량혹묘색약속기경도변형등유침대성적공정치리조시.
Taking two new and old landslides,located at Xingma Middle School and Dahe Middle School in Nanjiang County,Sichuan Province,as topical cases,a new translational landslide named plate-shaped landslide is presented analyzed through these two cases. The characteristics of such landslides are thin rectangular plate,with the length of the longitudinal axis of the plane shorter than the lateral axis. And it is like a thin plate in section. The main geological setting of this kind of landslide is thick sandstone rock bed inter-bedded with a mudstone rock bed on the bottom,in which there is a long discontinuity developed inside the slope which parallels to the slope angle. The discontinuity will develop into a tension crack when the heavy rainfall occurs and it will be infilled with water quickly till the water table reaches to a certain critical level. The hydrostatic pressure will push the block on the free side out and such movement will stop when the water table in the crack drops with the crack being large enough. A systematic study of the lithology background,tension crack contain water as well as the rainfall triggering factor condition is carried out. Based on the study,in light of the deformation pattern of the plate-shaped landslide,some measures to treat the landslide are provided,which include operating the drainage project to make sure the water can be drained in the crack,setting a short pile or anti-sliding block outside in the toe of slope to prevent the sliding movement,and setting beams or anchorage cables between the blocks on the top of slope to control the deformation which is caused by tension cracks.