为了得到矩形、拱形截面明洞土压力随填土高度的变化规律，采用模型试验与数值模拟相结合的方法进行研究，得到以下结果： 1）截面形式对明洞土压力大小影响很大，且基础刚度不同，差异性明显。拱形截面明洞洞顶轴线处竖向土压力大于矩形截面明洞。2）刚性基础拱形截面明洞洞顶同一平面竖向土压力变化呈减小—平缓的趋势，而柔性基础呈减小—增大—平缓的趋势； 矩形截面明洞呈增大—减小—平缓的趋势。3）刚性基础明洞洞顶同一平面水平土压力分布形式呈现出2个拱形，而柔性基础明洞仅在洞顶上方出现1个拱形。4）刚性基础拱形、矩形截面明洞洞顶至0.6倍洞高范围内土体位移分别呈“W”、“双V”形分布，0.6～3倍洞高内均呈“V”形分布，3倍洞高以上无相对沉降，而柔性基础明洞土体位移在0～3倍洞高内均为“V”形，3倍洞高以上无相对沉降。

The model test and numerical simulation are adopted to study the variation rule of earth pressure of rectangular and arched opencut tunnels with filling height. The results obtained include: (1) The tunnel crosssection form has a great influence on earth pressure, and the influence varies under different foundation stiffnesses. The vertical earth pressure on the top axis of opencut tunnel with arched crosssection is greater than that of opencut tunnel with rectangular crosssection. (2) The variations of conplane vertical earth pressures of arched opencut tunnel with rigid foundation and flexible foundation present a decreasinggentle trend and a decreasingincreasinggentle trend, respectively; and that of rectangular opencut tunnel presents an increasingdecreasinggentle trend. (3) Two arches are presented as the distribution forms of the conplane horizontal earth pressures of opencut tunnel with rigid foundation, while only one arch is appeared above the top of opencut tunnel with flexible foundation. (4) The soil displacements of rectangular and arched opencut tunnels with rigid foundation present a W shape and a dualV shape from the top to 0.6 times tunnel height, respectively; they present a V shape in the range of 0.6 to 3 times tunnel height, and no relative settlement occurs above 3 times tunnel height; the soil displacements of rectangular and arched opencut tunnels with flexible foundation present a V shape in the range of 0 to 3 times tunnel height, and no relative settlement occurs above 3 times tunnel height.