Classification standard of tunnel surrounding rock

The surrounding rocks of tunnels are divided into six categories: ⅵ, ⅴ, ⅴ, I, I, and the greater the number, the better the surrounding rock properties. The new code divides the surrounding rock of tunnel into six grades: I, I, I, IV, V and VI. The smaller the number, the better the surrounding rock properties. Therefore, the sea surrounding rocks in the old code are Class I surrounding rocks in the new code, and Class I surrounding rocks in the old code are Class V surrounding rocks in the new code. Tunnel surrounding rock is generally divided into six grades, the first grade surrounding rock is the best, basically a whole hard stone; The sixth grade surrounding rock is the worst, and it is basically scattered soft soil.

In engineering geology, the rock mass within the influence range of redistributed stress is called surrounding rock. Maximum 6R(r is the radius of the cavern)

A geological term, relative to the rocks around a bottom shell material. The common ones are magma surrounding rock and ore body surrounding rock. The surrounding rock of coal seam refers to the rock (soil) which has an influence on the stability of coal seam in a certain range around the coal body. Secondly, in the rock underground engineering, the stress state of surrounding rock has changed due to the influence of excavation.

Surrounding rock is the rock around the cavern, which can be excavated manually (such as various tunnels and underground warehouses, etc.). ) or naturally formed (such as caves, caves, etc.). ).

engineering properties

The engineering properties of surrounding rock generally include three aspects: physical properties, hydraulic properties and mechanical properties. The biggest factor affecting the stability of surrounding rock is mechanical properties, that is, the ability of surrounding rock to resist deformation and failure. The surrounding rock can be rock mass or soil.

Rock mass is a geological body formed by rock construction, structural deformation and secondary transformation in a long geographical history. It is cut into various blocks with different sizes and shapes by geological interfaces of fault planes, bedding planes, joint planes and fault planes in many different directions and sizes.

In engineering geology, these geological interfaces are called structural planes passing through discontinuities, and these blocks are called structural bodies. Rock mass is regarded as a geological body with structural characteristics composed of structural planes and structural bodies.

Environmental factors, especially groundwater and ground temperature, also have great influence on the mechanical properties of rock mass. Among many factors, which plays a leading role depends on specific conditions.

Legal basis:

Article 47 of People's Republic of China (PRC) Highway Law.

Within 200 meters around large and medium-sized highway bridges, highway tunnels and highway ferries, above the highway tunnels, outside the hole 100 meters, and within a certain distance on both sides of the highway, activities that endanger the safety of highways, highway bridges, highway tunnels and highway ferries, such as sand digging, quarrying, earth taking, dumping wastes and blasting, are not allowed. If it is necessary to build dams, compress or widen riverbeds within the scope of the preceding paragraph due to emergency rescue and flood control, it shall be reported in advance to the transportation departments of the people's governments of provinces, autonomous regions and municipalities directly under the Central Government for approval in conjunction with the water administrative departments, and effective measures shall be taken to protect the safety of relevant highways, highway bridges, highway tunnels and highway ferries.