引水隧洞岩体节理塑性区特征规律研究

Study on Characteristic Law of Rock Joint Plastic Zone of Water Diversion Tunnel

以某地区引水隧洞的塑性区规律为研究对象,基于摩尔-库仑准则,通过计算推导出岩体塑性区计算公式,并由此对其岩体开挖塑性区进行分析。结果表明,对于门洞形隧洞,会随侧压力系数的变化而变化,且其值越远离中心点,影响越大;同时塑性区会随着节理岩体内部扩展而趋势不规则,且其趋势会越来越明显,因此需要防止其内部扩展。通过软件模型可知,开挖时应做好支护工作,防止因开挖造成应力分布范围的扩大。研究成果对门洞形引水隧道塑性区的研究具有参考价值。

Taking the plastic zone law of a regional diversion tunnel as the research object,the formula for calculating the plastic zone of a rock body is derived by calculation based on the Moore-Coulomb criterion.The plastic zone of rock excavation is then analyzed.The results show that for portal-shaped tunnels,it will change with the change of lateral pressure coefficient,and the farther its value is from the center point,the greater the influence,and the plastic zone will expand with the internal expansion of the jointed rock mass,the trend is irregular,and its trend will become more and more obvious,so it needs to prevent its internal expansion.It is known from the software model that the excavation should be well supported to prevent the expansion of the stress distribution due to excavation.The numerical simulation of the diversion tunnel in this paper is a typical portal-shaped tunnel,and it is of reference value for the study of plastic zone in portal-shaped diversion tunnels.