岩土工程学报
巖土工程學報
암토공정학보
CHINESE JOURNAL OF GEOTECHNICAL ENGINEERING
2015年
4期
675-682
,共8页
李浩%罗强%张良%蒋良潍%张家国
李浩%囉彊%張良%蔣良濰%張傢國
리호%라강%장량%장량유%장가국
衡重式路肩墙%土工离心模型试验%位移模式%土压力%路基沉降%土拱效应
衡重式路肩牆%土工離心模型試驗%位移模式%土壓力%路基沉降%土拱效應
형중식로견장%토공리심모형시험%위이모식%토압력%로기침강%토공효응
shoulder balance weight retaining wall%centrifugal model test%motion mode%earth pressure%fill settlement%soil arching effect
以某山区公路旧路拓宽改造工程中新建的衡重式路肩挡土墙为原型,设计了墙体在平移(T)、绕墙趾转动(RB)、绕墙顶转动(RT)以及平移与绕墙趾转动复合形式(T+RB)4种位移模式的土工离心模型试验,讨论了挡墙位移模式对墙背土压力和路基填土变形的影响,分析了墙后不同深度土体进入主动状态的进程,试验表明:①位移模式对上墙土压力大小及分布形态基本无影响,但上墙浅层土体在挡墙位移与墙高比值小于0.3%~0.5%时,存在墙–土摩擦引起的土拱效应,使水平土压力系数增大;②由于衡重台的存在,对下墙距衡重台约1/3下墙高度范围的土压力有遮蔽作用,其结果是降低了土压力合力作用点位置;③位移模式对填土沉降有明显影响,在墙体位移最大值相同时,T位移模式的填土沉降明显大于RB和RT位移模式,而RT位移模式,衡重台向下偏转,促进了填土下沉,最终使其填土沉降大于相同位移面积的RB位移模式,也更容易使上墙出现第二破裂面。
以某山區公路舊路拓寬改造工程中新建的衡重式路肩擋土牆為原型,設計瞭牆體在平移(T)、繞牆趾轉動(RB)、繞牆頂轉動(RT)以及平移與繞牆趾轉動複閤形式(T+RB)4種位移模式的土工離心模型試驗,討論瞭擋牆位移模式對牆揹土壓力和路基填土變形的影響,分析瞭牆後不同深度土體進入主動狀態的進程,試驗錶明:①位移模式對上牆土壓力大小及分佈形態基本無影響,但上牆淺層土體在擋牆位移與牆高比值小于0.3%~0.5%時,存在牆–土摩抆引起的土拱效應,使水平土壓力繫數增大;②由于衡重檯的存在,對下牆距衡重檯約1/3下牆高度範圍的土壓力有遮蔽作用,其結果是降低瞭土壓力閤力作用點位置;③位移模式對填土沉降有明顯影響,在牆體位移最大值相同時,T位移模式的填土沉降明顯大于RB和RT位移模式,而RT位移模式,衡重檯嚮下偏轉,促進瞭填土下沉,最終使其填土沉降大于相同位移麵積的RB位移模式,也更容易使上牆齣現第二破裂麵。
이모산구공로구로탁관개조공정중신건적형중식로견당토장위원형,설계료장체재평이(T)、요장지전동(RB)、요장정전동(RT)이급평이여요장지전동복합형식(T+RB)4충위이모식적토공리심모형시험,토론료당장위이모식대장배토압력화로기전토변형적영향,분석료장후불동심도토체진입주동상태적진정,시험표명:①위이모식대상장토압력대소급분포형태기본무영향,단상장천층토체재당장위이여장고비치소우0.3%~0.5%시,존재장–토마찰인기적토공효응,사수평토압력계수증대;②유우형중태적존재,대하장거형중태약1/3하장고도범위적토압력유차폐작용,기결과시강저료토압력합력작용점위치;③위이모식대전토침강유명현영향,재장체위이최대치상동시,T위이모식적전토침강명현대우RB화RT위이모식,이RT위이모식,형중태향하편전,촉진료전토하침,최종사기전토침강대우상동위이면적적RB위이모식,야경용역사상장출현제이파렬면。
Using the new shoulder balance weight retaining wall of an old embankment widening project of a mountainous highway as the prototype, four groups of geotechnical centrifugal model tests are designed based on the wall motions under translation (T), rotating around base (RB), rotation around top (RT) and T+RB modes, the impact of wall motion modes on earth pressure and deformation of the filling is discussed, and the process of soils at various depths entering in to the active earth pressure is analyzed. The results show that: (1) The wall motion modes almost have no influence on the values and distribution of earth pressure on the upper wall, but when the ratio of displacement to height of retaining wall is less than 0.3%~0.5%, the shallow layer fills behind the upper wall have soil arching effect which is caused by wall-soil friction, and the coefficient of horizontal earth pressure increases; (2) The equilibrator has a shadowing effect on the down wall earth pressure, and the influence area is about 1/3 height of the down wall below the equilibrator. The results reduce the position of the acting point of earth pressure resultant force; (3) The motion modes have obvious impact on the fill settlement. When the maximum wall displacements are the same, the fill settlement of the T mode is significantly larger than that of the RB and RT modes. Under the RT mode, although it has the same displacement area as the RT mode, the equilibrator deflects downward. The fill settlement is promoted, leading to that the fill settlement of the RT mode is larger than that of RB mode, and the second fracture surface occurs easier on the upper wall.