Tunnelling works are subject to a variety of undesirable geological conditions that can lead to safety accidents. In order to ensure the safety of tunnel engineering, this article will introduce some safety precautions for poor geological conditions in tunnel engineering.
1. Overview of tunnel engineering.
Tunnel engineering is one of the most common forms of underground engineering, mainly through the excavation of underground space, the construction of tunnels to achieve the role of crossing mountains, rivers and other natural obstacles. Tunnel engineering has the characteristics of difficult construction, high technical requirements, and great influence by geological conditions, so when carrying out tunnel engineering construction, it is necessary to fully investigate and analyze the geological conditions to ensure construction safety.
2. Poor geological conditions of tunnel engineering.
Poor geological conditions often encountered in tunnel engineering include weak fracture zones, karst, water inflow, silty soil, high geostress, etc. These conditions will have a great impact on the construction safety of tunnel engineering.
1.Weak Fracture Zone.
When the tunnel project encounters a weak fracture zone, there are often problems such as collapse and roofing. This is because the geological conditions of the weak fracture zone are relatively poor, the rock mass is loose and broken, the stability is poor, and it cannot withstand the external force brought by the construction.
2.Karst.
Karst is a common geological hazard that is mainly formed due to the dissolution of groundwater to soluble rocks. Karst poses a great threat to the construction safety of tunnel engineering, especially in areas where karst is developed.
3.Rushing water.
Water inrush is a common problem in tunnelling projects. The water inflow is mainly due to the groundwater gushing out of the surrounding rock, which can have a significant impact on the tunnel construction. Especially in places where groundwater is abundant, water inrush may cause water to accumulate inside the tunnel, affecting construction safety.
4.Silty soils.
Silty soil is a kind of soft soil, which has the characteristics of high water content, high compressibility and low strength. When encountering silty soil, problems such as settlement and collapse may occur during the construction of tunnel engineering, which affects the construction safety.
5.High geostress.
High geostress mainly refers to the vertical pressure deep underground, which will have a great impact on the construction of tunnel engineering. High geostress can cause cracks, deformation and other problems in the surrounding rock, and also cause damage to the lining structure of the tunnel.
3. Safety precautions for poor geological conditions of tunnel engineering.
In order to ensure the safety of tunnel engineering in the event of adverse geological conditions, the following points need to be noted:
1.Investigate the geological conditions thoroughly.
Before the construction of the tunnel project, it is necessary to fully investigate and analyze the geological conditions, especially for the possible adverse geological conditions. In this way, we can better understand the local geology and provide a scientific basis for subsequent construction.
2.Strengthen the surrounding rock support.
In the case of poor geological conditions, it is necessary to strengthen the surrounding rock support measures. Bolts, shotcrete and other means can be used to improve the stability of the surrounding rock and prevent problems such as collapse and roofing. Especially in the areas of weak fracture zones and karst development, more stringent surrounding rock support measures must be taken.
3.Deal with water inrush in a timely manner.
In the event of a water inrush problem, measures must be taken to deal with it in a timely manner. Drainage, plugging and other means can be used to prevent the impact of water inrush on construction safety. Especially in places where groundwater is abundant, it is necessary to strengthen drainage measures for tunnels to ensure construction safety.
4.Rational treatment of silty soils.
When encountering silty soil, it must be treated reasonably. Soil replacement, drainage consolidation and other means can be used to improve the stability of silty soil and prevent problems such as settlement and collapse. Especially in places where the silt is thicker, more effective treatment measures must be taken.
5.Strengthen the treatment of high geostress.
In the event of high geostress, treatment measures must be strengthened. The means of releasing or reducing stress can be used to reduce the pressure of the surrounding rock and prevent cracks, deformation and other problems. Especially in places where high geostress is greater, more effective treatment measures must be taken.