寒旱区梯形渠道衬砌冻胀破坏数值模拟

Numerical Simulation Study on Frost Heaving Damage of Trapezoidal Channel Concrete Lining in Cold and Arid Area

针对刚性衬砌渠道冻胀破坏问题,选取宁夏盐环定扬黄灌区衬砌渠道为研究对象,在考虑相变及水分迁移模型基础上,考虑高地下水位对冻胀的影响,建立考虑水分迁移及地下水影响的数学物理模型,并采用Comsol Mutiphysics有限元软件对梯形渠道混凝土衬砌进行冻胀数值模拟,分别从温度场、位移场和应力场对刚性衬砌渠道冻胀破坏等方面进行了研究分析。结果表明:阴坡、阳坡冻胀量较大,渠底较小,渠底中部、渠坡1/3坡板长度处冻胀量分别达到最大值。渠底中部的法向冻胀力较小,两边逐渐增大,阴坡、阳坡的法向冻胀力分布均匀;渠底的切向冻结力成线性分布。阴坡、阳坡靠近坡脚处切向冻结力较大,左、右两端坡顶处切向冻结力较小,渠底衬砌板和两侧衬砌板属于压弯组合变形构件。

In view of the problem of frost heaving and damage of rigid lining channel , the lining channel ofYanhuanding irrigation area in Ningxia was selected as the research object. On the basis of the model considering phase change and water transfer , the influence of high ground water level on the frost heave was considered , a mathematical physical model considering water migration and the influence of groundwater was established and Comsol Mutiphysics was adopted. The finite element software was used to numerical simulate the frost heaving of the concrete lining of the trapezoid channel and the frost heaving damage of the rigid lining channel was studied and analyzed from the temperature field , the displacement field and the stress field respectively. The results show that the frost heaving amount of shady slope and sunny slope is large and the canal bottom is small. In the middle of the canal bottom , the frost heaving amount at the length of 1 / 3 of the canal slope reaches the maximum value respectively. The normal frost heave force in the middle of the canal bottom is smaller , the sides increase gradually , the normal frost heave force distribution on the shady slope and sunny slope is uniform and the tangential freezing force at the bottom of the canal is linearly distributed. The shady slope and the sunny slope close to the foot of the slope have a greater tangential freezing force , while the tangential freezing force is less at the top of the slope on the right and left ends , the bottom lining slab and the two lining slab are bent and combined deformation members. The correlative research can provide beneficial reference for the treatment of frost heaving damage and protection of lining channels in cold and dry irrigation areas.