穿江隧道对堤防工程影响研究

Study on the influence of the cross-river tunnel to the embankment project

采用数值方法,通过多工况模拟,分别对隧道的覆土厚度、隧道匝道出入口离堤防的距离、隧道主出入口与堤防的相对距离以及地下水等因素进行影响分析,研究堤防工程的渗透稳定及变形趋势。研究结果表明:在堤防工程的护堤地范围内,穿江隧道匝道出入口离堤防的距离越近且地下水位越低时,水力坡降越大,对堤防的渗流稳定越不利;但地下水位越高时,堤顶与地表沉降越大,对堤防的沉降稳定越不利。隧道覆土厚度几乎不影响堤防的水力坡降,但会影响堤防的沉降变形,覆土厚度必须按规范或经验限定。隧道主出入口与堤防的相对距离越近且地下水位越低时,水力坡降越大,但相对距离及地下水位的改变对沉降影响很小。

In this article the numerical method is used to simulate the seepage stability and deformation of the embankment engineering through multiple operating condition. By analysing tunnel＆#39;s cover thicknees, distance from the entrance of ramp to the embankment, relative distance from the major entrance to the embankment and ground water, the seepage stability and deformation of the embankment is studied. It turns out that within the scope of the levee engineering, with closer distance from cross-river tunnel ramp entrances and exits to dike and lower underground water level. The hydraulic grade will be greater, which has worse effect on the seepage stabili-ty of the dike. But the higher underground water level, the greater the settlement of levee crest and ground sur-face are, which has worse effect on settlement stabilization. The tunnel’ s cover thickness almost has no effect on the embankment’ s hydraulic gradient, but it does affect the embankment’ s settlement deformation. So that the cover thickness must be defined according to specifications or experience. With closer the distance from major en-trance to the embankment and lower ground water level, the hydraulic gradient will be greater, and the change of relative distance and groundwater level has little effect on settlement.