建立桩网结构路基的离散元模型，从散粒体和微观角度研究了桩网结构路基中的土拱效应。结果表明：土拱效应随着桩间土的沉降而发展变化，桩间土发生较大的沉降后土拱效应才能达到极限状态。桩顶平面上方1.67倍桩净间距范围内土体的密实度受土拱效应的影响，土体孔隙率的变化与土拱效应发展保持一致。土拱效应发展过程中土体的竖向位移远大于水平向位移，桩顶上方竖向位移小于桩间土上方竖向位移，等沉面的高度位于2.7倍的桩净间距处。土体中竖向应力的影响范围与密实度的影响范围相同，土拱高度为该影响范围的上限，在该范围内土压力系数随土拱效应发展而变化，但两者变化并不一致，且土压力系数在桩顶上方和桩间土上方也不相同。%Soil arching in pile supported geosynthetic-reinforced embankment is studied from granular and microcosmic viewpoint by using discrete element program. It indicates that soil arching develops with the settle-ments of soil between piles and it needs large settlement for soil arching to get ultimate state. Soil arching has an influence on soil density degree above pile within 1 . 67 times of clear pile spacing and the variation of porosity brings into correspondence with development of soil arching. The vertical displacements of soil are largely greater than horizontal displacements and vertical displacements of soil above piles are greater than that above soil be-tween piles. The height of plane which settlements of soil are equal is 2. 7 times of clear pile spacing and the height of soil arching is upper limit of scope which soil density degree and vertical stress are affected. The soil pressure coefficient, below the height of soil arching, varies with development of soil arching but the variation of them is inconsistent and soil pressure coefficients above pile and soil between piles are not equal.
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