摘要
由于圆形顶管掘进机的长高比为1,开挖面破坏时会形成卸荷拱,滑动块是一个形状复杂的截柱体,并非楔形体模型假定的三角形楔体。假定开挖面失稳时滑动块的形状为一个梯形楔体,滑动块上部为一梯形棱柱。采用太沙基松动土压力理论,根据滑动块的整体受力平衡,推导出砂性土中考虑成层土的开挖面最小支护压力计算公式。算例分析表明,该方法的计算结果要小于楔形体模型的计算结果,更接近离心模型试验结果。
The length-height ratio of circular shield is equal to 1, and thus the uploading arch will be formed when the face is destroyed. The sliding block is a truncated prism with complicated shape but not a triangular wedge as assumed by wedge stability model. The shape of sliding block and upside of sliding block are presumed as a trapezoid wedge and a trapezoid prism respectively. Using the theory of Terzaghi ＇ s relation soil pressure, the limited support pressure formula with tunnel face in stratified sandy soil is obtained based on the principle of sliding block entire force balance. It is shown in analytical calculation that, the calculation result by the method mentioned above is smaller when compared with that by wedge model, and also more closer to the results of centrifugal - model test.
出处
《地下空间与工程学报》
CSCD
2007年第5期903-908,共6页
Chinese Journal of Underground Space and Engineering
关键词
顶管
砂性土
开挖面
支护压力
pipe jacking
sandy soil
tunnel face
support pressure
