基于非均匀开孔透壁通风管级配碎石的青藏高原宽幅公路路堤阴阳坡调控机理研究

For the sunny-shady slope effect of the wide express highway in permafrost regions of the Qinghai-Tibet Plateau, it will be necessary to employ a new combined technique in the well-graded crushed rock embankment of asphalt highway embedded axial- nonuniformly perforated ventilation pipes and laid a thermal insulation layer. Mechanism of adjusting ground asymmetrical temperatures due to impacting of the sunny-shady slope effect by means of an enhanced asymmetrical cooling effect in the well-graded crushed rock embankment embedded nonuniformly perforated ventilation pipes is studied. The impact of key parameters such as location and spacing of ventilation pipes, nonuniform perforating form and perforating ratio of wall, temperature difference between the sunny and shady slopes, air temperature, wind velocity and slope boundary conditions on enhancing the asymmetrical cooling capability and adjusting the sunny-shady slope effect in the well-graded crushed rock embankment with nonuniformly perforated ventilation pipes is analyzed both theoretically and experimentally. A numerical simulation method of nonlinear finite element is developed to calculate three-dimensional heat convection of air-solid in the computational domain consisting of well-graded crushed rock embankment with nonuniformly perforated ventilation pipe, asphalt pavement layer, thermal insulation layer, active layer, permafrost layer and adjacent air. Under the scenario of climate warming, the symmetrical characteristics of temperature distribution and the long-term tendency of temperature change in the well-graded crushed rock embankment of wide asphalt highway with nonuniformly perforated ventilation pipes and underlying foundation soil are obtained by numerical simulation. Under such engineering conditions on the Qinghai-Tibet Plateau, the well-graded crushed rock embankment structure embedded nonuniformly perforated ventilation pipes and its application principle available for adjusting the sunny-shady slope effect of the wide highway embankment are obtained, so as to improve the key combined techniques for mitigating the sunny-shady slope effect and ensuring the heat stability of the wide expressway embankment in permafrost regions.

针对青藏高原冻土区高等级宽幅公路存在的阴阳坡问题,研究基于轴向非均匀开孔透壁通风管和保温层综合措施增强沥青公路级配碎石路堤不对称降温效果及其对阴阳坡导致的不对称温度分布的调控机理。通风管埋设位置及间距、管壁非均匀开孔形式及开孔率、两边边坡温差、气温、风速、边坡边界条件等参数对非均匀开孔透壁通风管增强级配碎石路堤的不对称降温效果及其对路堤阴阳坡的调控机理进行实验和理论研究,研究非均匀开孔透壁通风管级配碎石路堤、冻土层及相邻空气等区域中运用气固热对流三维耦合问题的非线性有限元数值模拟方法,通过数值模拟分析全球气候变暖条件下高等级宽幅沥青公路非均匀开孔透壁通风管级配碎石路堤及其土层的对称温度分布特征和长期趋势,获得适合青藏高原工程环境条件的能够调控宽幅路堤阴阳坡问题的非均匀开孔透壁通风管级配碎石路堤结构形式及其工程应用原则,改进能减轻冻土区高等级公路路堤阴阳坡问题、增强路基稳定性的关键技术措施。

针对青藏高原冻土区高等级宽幅公路存在的阴阳坡问题，研究基于轴向非均匀开孔透壁通风管和保温层综合措施增强沥青公路级配碎石路堤不对称降温效果及其对阴阳坡导致的不对称温度分布的调控机理。通风管埋设位置及间距、管壁非均匀开孔形式及开孔率、两边边坡温差、气温、风速、边坡边界条件等参数对非均匀开孔透壁通风管增强级配碎石路堤的不对称降温效果及其对路堤阴阳坡的调控机理进行实验和理论研究，研究非均匀开孔透壁通风管级配碎石路堤、冻土层及相邻空气等区域中运用气固热对流三维耦合问题的非线性有限元数值模拟方法，通过数值模拟分析全球气候变暖条件下高等级宽幅沥青公路非均匀开孔透壁通风管级配碎石路堤及其土层的对称温度分布特征和长期趋势，获得适合青藏高原工程环境条件的能够调控宽幅路堤阴阳坡问题的非均匀开孔透壁通风管级配碎石路堤结构形式及其工程应用原则，改进能减轻冻土区高等级公路路堤阴阳坡问题、增强路基稳定性的关键技术措施。