Scaffolding construction method used for super shallow buried large underground space

Abstract

The invention discloses a scaffolding construction method used for the super shallow buried large underground space. The scaffolding construction method comprises the steps that an underground excavation construction vertical shaft is conducted in a fence, and a horizontal transverse passage is formed in a vertical shaft; a first guide hole is formed in a selected location in underground space, and, and a transverse shed protection structure perpendicular to the excavation direction is arranged in the first guide hole; the first guide hole forms a girder, and a second guide hole is formed under the protection of the transverse shed protection structure; a third guide hole is excavated, and the third guide hole and the second guide hole are connected together; soil mass between the second guide hole and the third guide hole on the two sides are excavated, and diagonal bracing erection is conducted; soil mass below diagonal bracing is excavated to the bottom, back cover grille erection is conducted, and strip footing is casted; vertical support erection is conducted, and the diagonal bracing is removed by sections; and a permanent structure is arranged. Therefore, the scaffolding construction method can be applied to excavation of a single-layer three-span cross section with the excavation width of about 20 meters and the excavation height of more than 9 meters, and can be used for shallow-buried underground excavation and super shallow buried underground excavation, the excavation volume is small, the excavation step is less, construction conversion is less, the constructionrisk is low, and the comprehensive construction cost is low.

Description

technical field [0001] The invention relates to the technical field of urban underground space construction, in particular to a scaffolding construction method for ultra-shallow buried large underground spaces. Background technique [0002] With the acceleration of my country's urbanization process, the development rate and scale of urban underground space are increasing day by day. Rail transit, comprehensive pipe corridors, underground garages and various integrated facilities are being constructed on a large scale in my country's underground space. The construction of underground engineering in our country has entered a new era, and its construction scale and speed are rare in the history of underground engineering construction in the world. Usually, the construction methods of underground engineering include open-cut method, cover-excavation method and underground excavation method. [0003] Both the open cut method and the cover excavation method are based on natural g...

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to deal with projects in the field of ultra-shallow buried underground excavation.

At the same time, due to the use of the middle hole method and the side hole method, arching is required, and the arch will further increase the vertical height of the structure, thereby further increasing the buried depth of the structure, so that the structure does not have the possibility of ultra-shallow buried excavation

[0009] However, with the development of my country's productivity level, the external environment of urban underground space construction has become increasingly complex, and a large number of underground projects have lost the conditions for open-cut construction due to the restrictions of ground transportation, underground pipelines and other underground structures.

However, its elevation is limited, and it is difficult to meet the covering soil requirements required for shallow buried excavation. Therefore, there is an urgent need for construction methods that can adapt to ultra-shallow buried excavations.

[0010] (2) Excavation steps are complex, construction transitions are many, and construction risks are high

[0011] Compared with CD, CRD, and double-side wall pilot tunnel methods, the middle tunnel method and side tunnel method have more complex construction steps and more construction turns. Taking the middle tunnel method as an example, it needs to be divided into 15 caverns for excavation and support structures. The force conversion between the protective structure and the permanent force structure needs 6 times, and a total of 21 steps are required. The excavation sequence is very complicated and there are many construction conversions.

And every step of the excavation of the support structure, the workers need to directly face the face of the tunnel and the soil above the vault obliquely, and the construction risk is high

At the same time, according to years of implementation experience in shallow burial and underground excavation, a large number of risks in underground excavation construction are in the link of force conversion. The middle hole method and side hole method are characterized by more force conversion, which is doomed to be more risky in implementation.

[0012] (3) There are many construction joints in the structure, and the durability of the permanent stressed structure is difficult to guarantee

[0013] There are 10 construction joints in the cross-sectional direction of the structure, and one construction joint every 4-6m in the longitudinal direction. There are many joints, which makes it difficult to guarantee the durability of the permanent stressed structure

[0014] (4) The middle hole method and the side hole method must be set as an arched structure to ensure the safety of excavation, forming an unnecessary excavation area and causing a waste of elevation

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