Vertical shaft excavation pre-supporting structure

Abstract

The utility model discloses a vertical shaft excavation pre-supporting structure, which relates to the field of water diversion vertical shaft engineering of pumped storage power stations and comprises a fault and a vertical shaft to be excavated, the fault and the vertical shaft to be excavated intersect at a small angle, a fault rock mass is supported by an advanced pipe shed in an area to be excavated, the advanced pipe shed is grouted, and the advanced pipe shed inclines downwards. The advance pipe sheds incline towards the outer side by 10-20 degrees along the tunnel wall, drainage holes are formed in the upper portions of the advance pipe sheds, and the pre-supporting structure is excavated and implemented layer by layer. Pipe shed grouting is adopted to pre-reinforce the fault at the top of the vertical shaft excavation area, meanwhile, the drainage holes are adopted to reduce the underground water level in the fault, and the self-stabilization capacity of the fault zone in the vertical shaft excavation process can be effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of water diversion shaft engineering of a pumped storage power station, in particular to a shaft excavation pre-support structure. Background Art

[0002] The water diversion tunnel of a pumped storage power station needs to use a vertical shaft or an inclined shaft. When the vertical (inclined) shaft passes through a fault, especially a steeply inclined fault, the range of the vertical (inclined) shaft crossing the fault is large, and the collapse of the fault and the broken rock mass within its influence range will affect the construction safety. Once a collapse occurs, it is difficult to handle because the collapsed part is located at the top of the excavation area. The collapsed area may even be unable to stabilize itself, and the collapse range may continue to extend upward. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a pre-support structure for shaft excavation, which can improve the construction safety of the shaft passing through the fault and ensure the construction safety.

[0004] The utility model is realized through the following technical solutions.

[0005] The utility model provides a pre-support structure for shaft excavation, comprising a fault and a shaft to be excavated, wherein the fault intersects the shaft to be excavated at a small angle, an advanced pipe shed is adopted for support of the fault rock mass in the area to be excavated and the advanced pipe shed is grouted, the advanced pipe shed is inclined downward and inclined outwardly along the cave wall by 10 to 20 degrees, a drainage hole is arranged on the upper part of the advanced pipe shed, and the pre-support structure is excavated layer by layer.

[0006] Furthermore, the advance pipe shelf and drainage holes are arranged on the high elevation side of the fault.

[0007] Furthermore, the plane distribution range of the advanced pipe rack and drainage hole settings is the area that is directly opposite to the fault direction and covers 60° on both sides.

[0008] Furthermore, each fault exposed by excavation is backfilled with concrete.

[0009] Furthermore, an arch is set up in the surrounding rock of the shaft and a mesh is hung to spray concrete to cover the arch and support the anchor rods.

[0010] The beneficial effects of the utility model are:

[0011] The self-stabilizing capacity of the fault zone during shaft excavation can be effectively improved by using pipe-roof grouting to pre-reinforce the fault at the top of the shaft excavation area and using drainage holes to lower the groundwater level in the fault.

[0012] The safety of the upper rock mass during excavation is ensured through layer-by-layer concrete backfill and arch support + shotcrete support. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a relative relationship diagram between the vertical shaft and the fault of the utility model;

[0014] Figure 2 It is a longitudinal section view of the support structure of the utility model;

[0015] Figure 3 This is the expansion diagram of the advanced support of the utility model;

[0016] Figure 4 It is a cross-sectional view of the support structure of the utility model.

[0017] In the figure: 1. Vertical shaft; 2. Fault; 3. System arch and system mesh sprayed concrete; 4. Anchor rods (anchor piles); 5. Concrete (fault exposure area); 6. Drainage holes; 7. Advanced pipe shed; 8. Planar expansion range of pre-support; 9. Schematic diagram of layer-by-layer excavation. DETAILED DESCRIPTION

[0018] The following is a further description of the structures involved in the present invention or the technical terms used. These descriptions are merely examples of how the present invention is implemented and do not constitute any limitation to the present invention.

[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left" and "right" indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, unless otherwise clearly specified and limited, "connection", "fixation" and the like should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] This embodiment introduces a shaft excavation pre-support structure, such as Figure 1-4As shown, it includes a shaft 1 to be excavated and a fault 2. The shaft 1 to be excavated intersects the fault 2 at a small angle. The fault rock mass is supported by an advance pipe shed 7 in the area to be excavated and the advance pipe shed 7 is grouted. The advance pipe shed 7 is inclined downward and inclined 10 to 20 degrees outward along the cave wall. A drainage hole 6 is arranged on the upper part of the advance pipe shed 7. The pre-support structure is excavated layer by layer, see Figure 3 Schematic diagram of layer-by-layer excavation line 9.

[0022] As an optional embodiment, the advance pipe shelf 7 and the drainage hole 6 are arranged on the high elevation side of the fault, see Figure 2 .

[0023] As an optional embodiment, the plane distribution range of the advanced pipe rack 7 and the drainage hole 6 is directly facing the fault direction, and the area 8 covered by about 60° on the left and right sides, see Figure 1 .

[0024] As an optional embodiment, each excavated fault 2 is backfilled with concrete 5, see Figure 2 and 4 .

[0025] As an optional embodiment, the surrounding rock of the shaft 1 is provided with an arch frame and a mesh is hung with sprayed concrete 3 to cover the arch frame and support anchor rods 4 (anchor piles), see Figure 2 .

[0026] The advanced pipe scaffolding 7 and drainage hole 6 advanced support measures adopted for the fault, as well as the fault concrete replacement backfill 5, arch frame and mesh spraying concrete 3, and anchor rod 4 support measures are implemented layer by layer as each layer is excavated until the vertical shaft 1 passes through the entire fault 2. In addition to the vertical shaft, the pre-support structure and construction method can also be applied to the inclined shaft.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pre-support structure for shaft excavation, comprising a fault and a shaft to be excavated, wherein the fault intersects the shaft to be excavated at a small angle, and is characterized in that: The fault rock mass is supported by an advanced pipe shed in the area to be excavated and grouted. The advanced pipe shed is inclined downward and 10 to 20 degrees outward along the cave wall. Drain holes are set on the upper part of the advanced pipe shed. The pre-support structure is excavated layer by layer.

2. A shaft excavation pre-support structure according to claim 1, characterized in that: The advance pipe shed and drainage holes are set on the high elevation side of the fault.

3. A shaft excavation pre-support structure according to claim 1, characterized in that: The plane distribution range of the advanced pipe rack and drainage hole settings is the area covering 60° on both sides facing the fault direction.

4. A shaft excavation pre-support structure according to claim 1, characterized in that: Concrete backfill is used for each fault exposed by excavation.

5. A shaft excavation pre-support structure according to claim 1, characterized in that: An arch frame is erected in the surrounding rock of the shaft and a mesh is hung to spray concrete to cover the arch frame and support the anchor rods.

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