A method for excavating a water-rich soil hole-type spillway

Abstract

The present invention discloses a method for excavating a water-rich soil tunnel spillway. The method divides the entire spillway excavation section into several short-distance construction units along the depth direction, thereby reducing the depth span of the actual construction end. Each construction unit is then divided into an upper layer, a middle layer, and a lower layer, which are supported and excavated in sequence. Under the premise of ensuring construction efficiency, the loosening and collapse of the upper soil during the excavation process is further avoided. The tunnel spillway is divided into a left middle area, a right middle area, a left lower area, and a right lower area along the diameter-depth direction, and then side support and excavation are carried out in sequence according to the diameter-depth direction, and drainage pipes are promptly constructed, thereby further avoiding the loosening of the soil layer. An inclined stepped surface is constructed on the top of each construction unit, and the inclined stepped surfaces of the upper layers of adjacent construction units are sequentially connected to form an overall inclined slope surface, so that slag produced during the excavation process can be quickly discharged to the outside of the tunnel spillway along the overall inclined slope surface, thereby achieving timely slag discharge.

Description

Technical Field

[0001] The invention belongs to the technical field of spillway excavation construction, and in particular relates to a method for excavating a water-rich soil hole-type spillway. Background Art

[0002] A tunnel spillway is a flood control and drainage structure used in road and bridge projects to quickly drain excess floodwater from bridge facilities. Traditional tunnel spillways can be constructed using methods such as blasting and excavation. However, for tunnel spillways in water-rich soil areas, since the water-rich soil is relatively loose, excavation methods such as blasting can easily cause soil collapse. Therefore, tunnel spillways in water-rich soil areas are usually constructed using a layered excavation method. However, in the existing layered excavation of tunnel spillways, due to the long depth of the spillway, even if layered excavation is used, it is easy for the soil above and on top of the spillway to loosen and collapse during the excavation process. However, the excavation method of first excavating a central guide tunnel and then expanding the excavation to form a spillway makes it difficult to discharge the excavated soil debris in a timely manner, and the expansion of the excavation can also cause the collapse of the upper soil layer.

[0003] Therefore, in order to solve the problems that it is difficult to ensure soil stability and slag discharge during the excavation of existing cave spillways in water-rich soil areas, the present invention discloses a method for excavating cave spillways in water-rich soil. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for excavating a cave spillway in water-rich soil, which can take into account the fact that the soil layer in water-rich soil areas is easily loose, and can carry out stable and safe excavation construction of the cave spillway in water-rich soil areas, effectively avoiding soil collapse during the excavation process.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for excavating a water-rich soil hole-type spillway comprises the following steps:

[0007] Step 1: Divide the spillway excavation section into several construction units along the depth direction of the spillway, and divide each construction unit into upper, middle, and lower layers from top to bottom;

[0008] Step 2: Excavating the upper layer of each construction unit along the depth direction of the spillway to form an inclined stepped surface, and connecting the inclined stepped surfaces of the upper layer excavations of adjacent construction units in sequence to form an overall inclined slope surface;

[0009] Step 3: Temporary support piles are placed in the middle and lower layers of each construction unit. Then, the construction units are excavated in sequence in the direction from the elevation of the overall inclined slope to the lower elevation. The excavated soil is discharged through the overall inclined slope.

[0010] Step 4: After the excavation of the middle and lower layers of the current construction unit is completed, an intermediate support is applied at the central axis of the current construction unit, and temporary support is applied to the side walls of the retaining wall construction unit based on the intermediate support;

[0011] Step 5: Repeat steps 3 and 4 above until all construction units are excavated and supported to form a tunnel spillway. Then, hang a mesh on the tunnel wall of the tunnel spillway and spray concrete for reinforcement.

[0012] Step 6: Remove the temporary support and intermediate support, and then clear the slag from the tunnel spillway.

[0013] In order to better implement the present invention, it is further characterized in that the step 3 includes:

[0014] Step 3.1. Divide the middle soil layer into a left middle area and a right middle area along the radial depth direction of the spillway, and divide the lower soil layer into a left lower area and a right lower area;

[0015] Step 3.2: Build temporary support in the left middle area, excavate the right middle area to the top of the lower soil layer, and then build a drainage pipe in the right middle area;

[0016] Step 3.2: Excavate the left middle area to the top of the lower soil layer, and at the same time, provide temporary support in the lower right area;

[0017] Step 3.3: Excavate the lower left area and construct a drainage pipe in the lower left area;

[0018] Step 3.4: Excavate the lower right area.

[0019] In order to better realize the present invention, further, a waterproof cloth layer is applied on the overall inclined slope surface, and the soil excavated in the current construction unit is discharged to the lower level of the overall inclined slope surface through the waterproof cloth layer.

[0020] In order to better implement the present invention, further, step 4 includes:

[0021] Step 4.1: Install a steel mesh at the bottom center of the current construction unit as the construction foundation for the intermediate support;

[0022] Step 4.2: Build the intermediate support upwards based on the steel mesh. When the height of the intermediate support exceeds half of the tunnel spillway elevation, build side supports on both sides of the intermediate support that connect to the side walls of the tunnel spillway.

[0023] Step 4.3: construct intermediate support up to the crown of the tunnel spillway, and construct crown support for the crown of the tunnel spillway based on the top of the intermediate support.

[0024] In order to better implement the present invention, further, before applying the intermediate support, a waterproof layer is applied to the bottom, side walls and arch of the cave spillway in advance.

[0025] In order to better implement the present invention, further, the inclined step surface includes a first inclined surface, a buffer plane, and a second inclined surface connected in sequence, and the longitudinal depth of the first inclined surface is greater than or equal to the sum of the longitudinal depth of the buffer plane and the longitudinal depth of the second inclined surface.

[0026] In order to better implement the present invention, further, the inclination angle of the first inclined plane is 8-15°, and the inclination angle of the second inclined plane is 15-30°.

[0027] In order to better implement the present invention, further, the depth of the construction unit is less than or equal to 10m.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] (1) The present invention divides the entire spillway excavation section into several short-distance construction units along the depth direction of the tunnel spillway, thereby reducing the depth span of the actual construction end. Then, each construction unit is divided into upper, middle and lower layers, which are supported and excavated in sequence. Under the premise of ensuring construction efficiency, the loosening and collapse of the upper soil during the excavation process is further avoided;

[0030] (2) The present invention further avoids soil loosening by dividing the tunnel spillway into the left middle area, the right middle area, the left lower area, and the right lower area along the diameter-depth direction, then carrying out side support excavation in sequence according to the diameter-depth direction, and constructing drainage pipes in a timely manner;

[0031] (3) The present invention constructs an inclined step surface on the top of each construction unit, and connects the inclined step surfaces of the upper layers of adjacent construction units in sequence to form an overall inclined slope surface, so that the slag produced during the excavation process can be quickly discharged to the outside of the tunnel-type spillway along the overall inclined slope surface, thereby achieving timely slag discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of excavating a stepped slope on the upper level of the construction unit;

[0033] Figure 2 It is a schematic diagram of the construction unit of elevation excavation on the overall inclined slope surface;

[0034] Figure 3 It is a schematic diagram of the lower layer of the excavation construction unit;

[0035] Figure 4 This is a schematic diagram of the construction of the intermediate support at the central axis of the excavated middle unit;

[0036] Figure 5 for Figure 4 AA sectional view;

[0037] Figure 6 This is a schematic diagram of the excavation in the right middle area of ​​the construction unit;

[0038] Figure 7 This is a schematic diagram of the excavation in the left middle area of ​​the construction unit;

[0039] Figure 8 This is a schematic diagram of the excavation in the lower left area of ​​the construction unit;

[0040] Figure 9 Schematic diagram of excavation in the lower right area of ​​the construction unit

[0041] Figure 10 This is a construction diagram of the intermediate support;

[0042] Figure 11 This is a schematic diagram of temporary support construction based on intermediate support;

[0043] Figure 12 This is a schematic diagram of the construction of spraying concrete with mesh hanging on the wall of the spillway;

[0044] Figure 13 Schematic diagram of dismantling intermediate support and temporary support. DETAILED DESCRIPTION

[0045] Example 1:

[0046] A method for excavating a water-rich soil tunnel spillway in this embodiment includes the following steps:

[0047] Step 1: Divide the spillway excavation section into several construction units along the depth direction of the spillway, and divide each construction unit into upper, middle, and lower layers from top to bottom;

[0048] like Figure 1 and Figure 5 As shown, the spillway excavation section is divided into three construction units along the depth direction of the spillway, and each construction unit is divided into upper, middle and lower layers from top to bottom. For water-rich soil, the height of the upper layer of each construction unit is less than or equal to one third of the spillway height.

[0049] Step 2: Excavating the upper layer of each construction unit along the depth direction of the spillway to form an inclined stepped surface, and connecting the inclined stepped surfaces of the upper layer excavations of adjacent construction units in sequence to form an overall inclined slope surface;

[0050] like Figure 1As shown, an inclined stepped surface is formed in the upper layer of each construction unit in turn, and the inclined stepped surfaces of the upper layers of adjacent construction units are connected to form an integral inclined slope surface, which is used as a slag discharge surface for subsequent excavation construction units.

[0051] Step 3: Temporary support piles are placed in the middle and lower layers of each construction unit. Then, the construction units are excavated in sequence in the direction from the elevation of the overall inclined slope to the lower elevation. The excavated soil is discharged through the overall inclined slope.

[0052] like Figure 2 As shown in the figure, temporary support is applied to the middle layer of the construction unit; Figure 3 As shown, the middle layer of the construction unit is excavated, and temporary support is applied to the lower layer of the construction unit. After the construction unit at the higher level is completely excavated and drained and de-slaged according to step 3, the next construction unit is excavated in the direction from the higher level to the lower level.

[0053] Step 4: After the excavation of the middle and lower layers of the current construction unit is completed, an intermediate support is applied at the central axis of the current construction unit, and temporary support is applied to the side walls of the retaining wall construction unit based on the intermediate support. Figure 4 As shown, after the excavation of the middle and lower layers of the construction unit is completed, the intermediate support is applied.

[0054] Step 5: Repeat steps 3 and 4 above until all construction units are excavated and supported to form a tunnel spillway. Then, hang a mesh on the tunnel wall of the tunnel spillway and spray concrete for reinforcement.

[0055] Step 6: Remove the temporary support and intermediate support, and then clear the slag from the tunnel spillway.

[0056] Example 2:

[0057] This embodiment is further optimized based on the above embodiment 1, and step 3 includes:

[0058] Step 3.1, such as Figure 5 As shown, along the radial depth direction of the spillway, the soil in the middle layer is divided into the left middle area and the right middle area, and the soil in the lower layer is divided into the left lower area and the right lower area;

[0059] Step 3.2, such as Figure 6 and Figure 7 As shown, temporary support is constructed in the left middle area, and the right middle area is excavated to the top of the lower soil layer, and then a drainage pipe is constructed in the right middle area;

[0060] Step 3.2, such as Figure 8 As shown, excavate the left middle area to the top of the lower soil layer, and at the same time, provide temporary support in the lower right area;

[0061] Step 3.3, such as Figure 9 As shown, the lower left area is excavated and a drainage pipe is constructed in the lower left area;

[0062] Step 3.4: Excavate the lower right area.

[0063] The rest of this embodiment is the same as that of embodiment 1, so it will not be described again.

[0064] Example 3:

[0065] This embodiment is further optimized based on the above embodiment 1 or 2. Figure 2 As shown, a waterproof cloth layer is applied on the overall inclined slope surface, and the soil excavated in the current construction unit is discharged to the lower level of the overall inclined slope surface through the waterproof cloth layer.

[0066] The waterproof cloth layer is laid directly on the overall inclined slope. Compaction air bags are set on the top of both sides of the waterproof cloth layer close to the cave wall to fix the waterproof cloth layer. At the same time, the air bags are used to block the soil unloading along the waterproof cloth layer, so that the soil can slide smoothly along the waterproof cloth layer.

[0067] The rest of this embodiment is the same as that of the above-mentioned embodiment 1 or 2, and thus will not be described in detail.

[0068] Example 4:

[0069] This embodiment is further optimized based on any one of the above embodiments 1-3. Figure 10-13 As shown, step 4 includes:

[0070] Step 4.1: Install a steel mesh at the bottom center of the current construction unit as the construction foundation for the intermediate support;

[0071] Step 4.2: Build the intermediate support upwards based on the steel mesh. When the height of the intermediate support exceeds half of the tunnel spillway elevation, build side supports on both sides of the intermediate support that connect to the side walls of the tunnel spillway.

[0072] Step 4.3: construct intermediate support up to the crown of the tunnel spillway, and construct crown support for the crown of the tunnel spillway based on the top of the intermediate support.

[0073] Furthermore, before applying the intermediate support, a waterproof layer is applied to the bottom, side walls and arch of the tunnel spillway.

[0074] The rest of this embodiment is the same as any of the above embodiments 1-3, so it will not be repeated here.

[0075] Example 5:

[0076] This embodiment is further optimized based on any one of the above embodiments 1-4, and the inclined step surface includes a first inclined surface, a buffer plane, and a second inclined surface connected in sequence, and the longitudinal depth of the first inclined surface is greater than or equal to the sum of the longitudinal depth of the buffer plane and the longitudinal depth of the second inclined surface.

[0077] The inclination angle of the first inclined plane is 8-15°, and the inclination angle of the second inclined plane is 15-30°.

[0078] The rest of this embodiment is the same as any of the above embodiments 1-4, so it will not be repeated here.

[0079] Example 6:

[0080] This embodiment is further optimized based on any one of the above embodiments 1-5, and the depth of the construction unit is less than or equal to 10m.

[0081] The rest of this embodiment is the same as any of the above embodiments 1-5, so it will not be repeated here.

[0082] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for excavating a water-rich soil tunnel spillway, characterized in that: The following steps are involved: Step 1: Divide the spillway excavation section into several construction units along the depth direction of the spillway, and divide each construction unit into upper, middle, and lower layers from top to bottom; Step 2: Excavating the upper layer of each construction unit along the depth direction of the spillway to form an inclined stepped surface, and connecting the inclined stepped surfaces of the upper layer excavations of adjacent construction units in sequence to form an overall inclined slope surface; Step 3: Temporary support piles are placed in the middle and lower layers of each construction unit. Then, the construction units are excavated in sequence in the direction from the elevation of the overall inclined slope to the lower elevation. The excavated soil is discharged through the overall inclined slope. Step 4: After the excavation of the middle and lower layers of the current construction unit is completed, an intermediate support is applied at the central axis of the current construction unit, and temporary support is applied to the side walls of the retaining wall construction unit based on the intermediate support; Step 5: Repeat steps 3 and 4 above until all construction units are excavated and supported to form a tunnel spillway. Then, hang a mesh on the tunnel wall of the tunnel spillway and spray concrete for reinforcement. Step 6: Remove the temporary support and intermediate support, and then clear the slag from the tunnel spillway.

2. The method for excavating a water-rich soil tunnel spillway according to claim 1, characterized in that: The step 3 comprises: Step 3.

1. Divide the middle soil layer into a left middle area and a right middle area along the radial depth direction of the spillway, and divide the lower soil layer into a left lower area and a right lower area; Step 3.2: Build temporary support in the left middle area, excavate the right middle area to the top of the lower soil layer, and then build a drainage pipe in the right middle area; Step 3.2: Excavate the left middle area to the top of the lower soil layer, and at the same time, provide temporary support in the lower right area; Step 3.3: Excavate the lower left area and construct a drainage pipe in the lower left area; Step 3.4: Excavate the lower right area.

3. The method for excavating a water-rich soil tunnel spillway according to claim 2, wherein: A waterproof cloth layer is applied on the overall inclined slope surface, and the soil excavated in the current construction unit is discharged to the lower level of the overall inclined slope surface through the waterproof cloth layer.

4. A method for excavating a water-rich soil tunnel spillway according to any one of claims 1 to 3, characterized in that: The step 4 comprises: Step 4.1: Install a steel mesh at the bottom center of the current construction unit as the construction foundation for the intermediate support; Step 4.2: Build the intermediate support upwards based on the steel mesh. When the height of the intermediate support exceeds half of the tunnel spillway elevation, build side supports on both sides of the intermediate support that connect to the side walls of the tunnel spillway. Step 4.3: construct intermediate support up to the crown of the tunnel spillway, and construct crown support for the crown of the tunnel spillway based on the top of the intermediate support.

5. A method for excavating a water-rich soil tunnel spillway according to claim 4, characterized in that: Before applying the intermediate support, a waterproof layer is applied to the bottom, side walls and arch of the tunnel spillway.

6. A method for excavating a water-rich soil tunnel spillway according to any one of claims 1 to 3, characterized in that: The inclined stepped surface includes a first inclined surface, a buffer plane, and a second inclined surface connected in sequence. The depth of the first inclined surface is greater than or equal to the sum of the depths of the buffer plane and the second inclined surface.

7. A method for excavating a water-rich soil tunnel spillway according to claim 6, characterized in that: The inclination angle of the first inclined plane is 8-15°, and the inclination angle of the second inclined plane is 15-30°.

8. A method for excavating a water-rich soil tunnel spillway according to any one of claims 1 to 3, characterized in that: The depth of the construction unit is less than or equal to 10m.

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