There are several ways to excavate tunnels

There are many kinds, and here are three kinds.

Full-section excavation method.

The full-section excavation method is suitable for tunnel construction with stable soil quality and small cross-section, and is suitable for manual excavation or small mechanical operation.

The full-section excavation method adopts top-to-bottom excavation forming, excavates along the contour, and excavates according to the construction plan.

One footage and timely initial support.

The advantage of the full-section excavation method is that it can reduce the number of disturbances of the excavation to the surrounding rock, which is conducive to the formation of the natural bearing arch of the surrounding rock, and the process is simple. The disadvantage is that the geological conditions are strict, and the surrounding rock must have sufficient self-stabilization ability.

Step excavation method.

The step excavation method is suitable for tunnel construction with good soil quality, weak surrounding rock, and Quaternary sedimentary stratum tunnels.

The step excavation method divides the structural section into more than two parts, that is, it is divided into two working faces or several working faces, and excavates step by step. According to the formation conditions and mechanical matching.

The step method can be divided into the positive step method and the middle next step method. The positive step method can close the support earlier, which is conducive to controlling the structural deformation and the resulting ground settlement.

The advantages of the step excavation method are that it has sufficient working space and fast construction speed, is flexible and changeable, and has strong applicability.

Annular excavation reserved core soil method.

The annular excavation reserved core soil method is suitable for the construction of tunnels with general soil or weak surrounding rock and large cross-section.

In general, the section is divided into three parts: the annular arch, the upper core soil, and the lower step. According to the size of the section, the annular arch can be divided into several pieces for alternating excavation. The footage of annular excavation is, OM should not be too long.

The length of the steps is generally controlled within 1d (d-generally refers to the tunnel span).

Construction operation process: use manual or single-arm TBM to excavate a vertical steel support of the annular arch and spray concrete. Under the protection of the initial support of the arch, in order to speed up the progress, it is advisable to use an excavator or a single-arm roadheader to excavate the core soil and the first step, and connect the long steel support and shotcrete and bottom sealing at any time.

Depending on the deformation of the primary support or the construction sequence, arrange the construction of the secondary lining operation.

Answer]: b, c, d, e

According to the characteristics of the stratum excavation method, the tunnel excavation method can be divided into the mining method (Changxiang uses the drilling and blasting method for construction), the shield method, the roadheader method and the jacking method.

Summary. Hello owner<>

For underground engineering excavation, it is called the construction method that is different from the underground excavation method: the open excavation method is to use the pre-applied enclosure structure, start from the ground and dig down to the place where you want to do the structure, and then backfill it after the structure is completed and return to the original state The ground excavation method is to excavate directly inside the soil, and there is no need to dig down from the ground (of course, the shaft and the working well still need to be excavated). In short, the open excavation method is a construction method in which others can be seen excavating on the ground, and the underground excavation method is a construction method in which the excavation below can not be seen on the ground.

Of course, there are also cover excavation methods and other construction methods, which are between the open excavation method and the dark excavation method. Generally speaking, the open cut method is cheaper, the construction is more reliable, the safety is high, and the quality of the main structure can be guaranteed, but the impact on the surrounding traffic is greater during construction. The underground excavation method is relatively expensive and the construction risk is large, but it has no impact on the road traffic on the ground during construction, and is especially suitable for the city center and some structures with deep burial.

For underground engineering excavation, what is it called as a construction method that is different from the underground excavation method?

Hello owner<>

For underground engineering excavation, it is called the construction method that is different from the underground excavation method: the open excavation method is to use the pre-applied enclosure structure, start from the ground and dig down to the place where you want to do the structure, and then backfill it after the structure is completed and return to the original state The ground excavation method is to directly excavate and bend the excavation directly inside the soil, and there is no need to dig down from the ground (of course, the shaft and the working shaft still need to be excavated). In short, the open excavation method is a construction method in which others can be seen excavating on the ground, and the underground excavation method is a construction method in which the excavation below can not be seen on the ground.

Of course, there are also cover excavation methods and other construction methods, which are between the open excavation method and the dark excavation method. Generally speaking, the open-cut method is cheaper, the construction is more reliable, the safety is high, and the quality of the main body is guaranteed to be scattered, but the impact on the surrounding traffic is greater during construction. The underground excavation method is relatively high in terms of construction and distribution, and the construction risk is large, but it has no impact on the road traffic on the ground during construction, and is especially suitable for the city center and some structures buried deeply.

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