建筑机械偏心荷载对开挖过程中沟槽稳定性的影响研究

通过在离心场中模拟沟槽开挖过程的模型试验,讨论挖掘机等建筑机械在开挖市政管线的沟槽过程中产生的偏心荷载对沟槽稳定性的影响。试验结果表明,沟槽的破坏形态与挖掘机中心荷载作用情况下相同。据此,可利用在中心荷载作用下求得的开挖深度极限分析上限解简化式,计算建筑机械偏心荷载作用下的沟槽开挖深度,并且所得计算结果与试验结果基本吻合。结果表明:偏心距对开挖深度的影响程度因挖掘机接触压力不同而不同。挖掘机接触压力越大,偏心距对开挖深度的影响也越大。

Influence of construction machinery eccentric load on stability of trench excavation

The influence of the construction machinery eccentric load on trench stability was studied by centrifuge model tests simulating the process of trench excavation.It was shown that the failure mechanism agreed well with that under the central load of construction machine.Therefore,the simplified expression for the upper-bound of excavation depth under the central load could be applied to that under the construction machinery eccentric load.The validity of the results from the simplified expression for the upper-bound solution was confirmed by comparing with the centrifuge test results.It was indicated that the influence of eccentricity on excavation depth increased with the increase of contact pressure.