Temporary supporting structure for strong unloading rock slope excavation

Abstract

The utility model discloses a strong unloading rock mass slope excavation temporary supporting structure in the technical field of slope engineering, which comprises a natural slope, a plurality of stages of excavation slopes and a plurality of fore shaft anchor bar piles, the plurality of stages of excavation slopes are positioned on one side of the natural slope, and the fore shaft anchor bar piles are positioned on the other side of the natural slope. The locking anchor bar piles are arranged at the top of the upper end excavation slope and the inner sides of riding tracks of all stages of excavation slopes, steel wire meshes are laid on the surfaces of the multiple stages of excavation slopes from top to bottom, temporary net hanging sprayed concrete is arranged on the surfaces of the steel wire meshes, and every two adjacent pieces of temporary net hanging sprayed concrete are in lap joint through the locking anchor bar piles. The excavation slope, the locking anchor bar piles, the temporary net hanging sprayed concrete and the steel wire net are arranged in a matched mode, so that the supporting structure is more rapid in excavation, the number of invested personnel is small, rainwater invasion in the construction period is reduced through rapid closing, the slope exposure time is shortened, the stable state of the slope is easily maintained, and the construction efficiency is improved. And the development of unloading relaxation is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of side slope engineering especially to a strong unloading rock mass side slope excavation temporary support structure. BACKGROUND

[0002] The strong unloading broken rock mass is a geological condition often encountered in water conservancy, highway and railway engineering, and has the following characteristics: ① scattered, fissure development, broken loose, hole wall easy to collapse, easy to occur sticking drill condition; 2, hard, compared with general loose broken stratum, rock hardness is big, drill tool abrasion is big; 3, leakage, side slope unloading degree is deep, crack development is wide, there is intercommunication, and the situation of hole leakage, grouting loss is serious; 4, sandwich, there are multiple faults in the part, and the stratum soft and hard interbedded performance is obvious. For highway and railway, it can reduce its influence on engineering construction by passing through mountain tunnel, but in water conservancy engineering, in order to ensure the safety of important permanent buildings such as dam, workshop, water inlet and outlet, it is necessary to carry out slope excavation, and often form more than 100m high side slope.

[0003] The strong unloading rock mass geological condition is complex, especially after being disturbed by blasting in the excavation process, the surface rock mass quality will be further deteriorated, and the stability is poor from the side slope excavation to the support implementation, especially when the side slope exists steep angle structural plane and gentle angle structural plane, unloading relaxation is easy to produce, which leads to the risk of local collapse or toppling deformation of the side slope after excavation, which endangers the safety of the side slope, based on this, we provide a strong unloading rock mass side slope excavation temporary support structure. UTILITY MODEL CONTENTS

[0004] In order to improve the above-mentioned existing side slope in the excavation process after being disturbed by blasting, the surface rock mass quality will be further deteriorated, and the stability is poor from the side slope excavation to the support implementation, especially when the side slope exists steep angle structural plane and gentle angle structural plane, unloading relaxation is easy to produce, the utility model provides a strong unloading rock mass side slope excavation temporary support structure.

[0005] The utility model provides a kind of strong unloading rock mass side slope excavation temporary support structure, using the following technical scheme:

[0006] A kind of strong unloading rock mass side slope excavation temporary support structure, including natural side slope, several levels of excavation side slope and several lock mouth anchor bars, several levels of the excavation side slope are located in the side of natural side slope, and several lock mouth anchor bars are set in the top of upper end excavation side slope and the inner side of each level of excavation side slope, the surface of several levels of the excavation side slope is all laid with steel wire mesh from top to bottom, and one end of steel wire mesh is fixedly connected with the top of lock mouth anchor bar, the surface of several steel wire meshes is all provided with temporary net-spraying concrete, and adjacent two temporary net-spraying concretes are overlapped by lock mouth anchor bar.

[0007] By adopting the technical scheme, firstly, the lock mouth anchor bar pile is arranged on the top of the excavation slope, and the lock mouth anchor bar pile is arranged obliquely in the mountain, after the first stage of slope excavation is completed and the horse path is cleaned, the steel wire mesh is laid from the top to the outside edge of the horse path at the bottom of the excavation slope, the steel wire mesh is firmly connected with the lock mouth anchor bar pile, then the temporary net-spraying concrete is sprayed, the initial support of the first stage of slope is completed, and the above steps are repeated to excavate downward, the temporary support structure is excavated quickly, and the personnel is less, so that the quick sealing reduces rainwater invasion during construction, reduces the exposure time of the slope, is favorable for maintaining the stable state of the slope, and reduces the development of unloading relaxation.

[0008] Optionally, the inside of the lock mouth anchor bar pile is provided with a steel bar, and the steel bar is bound and connected with one end of the steel wire mesh.

[0009] By adopting the technical scheme, the overall structural strength of the lock mouth anchor bar pile can be enhanced, so that the connection performance of the steel wire mesh and the lock mouth anchor bar pile is increased, and the support structure is more stable and firm when bearing external load.

[0010] Optionally, the thickness of the temporary net-spraying concrete is 5cm-10cm.

[0011] By adopting the technical scheme, the slope can be effectively reinforced, a protective layer is formed, the soil body can be prevented from being damaged by external factors such as water flow, the erosion of the slope soil flow is reduced, and the stability of the slope is improved.

[0012] Optionally, the steel wire mesh is a finished steel wire mesh.

[0013] By adopting the technical scheme, the steel wire mesh has strong flexibility as a whole, is laid close to the slope surface from top to bottom, the construction difficulty and cost are reduced, and the risk of personnel setting the steel wire mesh along the slope surface is reduced.

[0014] Optionally, the lock mouth anchor bar piles are all arranged obliquely in the mountain.

[0015] By adopting the technical scheme, the lock mouth anchor bar piles arranged obliquely in the mountain have a certain pre-protection effect on the excavation of the lower stage of slope, and the deformation and cracking problems caused by the excavation disturbance of the top rock mass are reduced.

[0016] Optionally, the distance between the end of the steel wire mesh and the outside edge of the horse path at the bottom of the excavation slope is 0.5m-1m.

[0017] By adopting the technical scheme, the stability during slope support is further improved.

[0018] In summary, the utility model has at least one of the following beneficial effects:

[0019] By combining the excavation of the slope, the anchor piles, the temporary mesh sprayed concrete and wire mesh, the support structure can be excavated more quickly and with fewer personnel. The rapid closure not only reduces rainwater intrusion during construction and shortens the time the slope is exposed, but also helps maintain the stability of the slope and reduces the development of unloading relaxation.

[0020] By arranging the anchor piles at an angle towards the mountain, a certain degree of pre-protection is provided for the excavation of the lower slope, reducing deformation and cracking caused by the disturbance of the top rock mass during excavation. At the same time, the temporary mesh shotcrete is connected to the upper temporary mesh shotcrete through the anchor piles, which enhances the restraint effect of the temporary mesh shotcrete on the slope, thereby improving the temporary stability of the slope.

[0021] By setting up temporary wire mesh and shotcrete, the safety risks caused by slope loosening and rockfall are effectively reduced. When the slope unloading and relaxation further develops, the cracks appearing on the surface of the temporary wire mesh and shotcrete can serve as an early warning function, reducing the safety risks of slope excavation and support construction. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of the excavated slope of this utility model.

[0025] In the diagram: 1. Natural slope; 2. Excavated slope; 3. Locking anchor piles; 4. Temporary wire mesh and shotcrete; 5. Reinforcing bars; 6. Wire mesh. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-2 The present invention will be described in further detail below.

[0027] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 This utility model provides an embodiment of a temporary support structure for excavating a strongly unloaded rock slope, comprising a natural slope 1, several levels of excavated slopes 2, and several anchor piles 3, all of which are arranged obliquely into the mountainside. The anchor piles 3 arranged obliquely into the mountainside provide a certain degree of pre-protection for the excavation of the lower slopes, reducing deformation and cracking problems caused by disturbance during the excavation of the top rock mass.

[0028] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 Several levels of excavated slope 2 are located on one side of the natural slope 1. Several interlocking anchor piles 3 are set at the top of the upper excavated slope 2 and inside the ramps of each level of excavated slope 2. The surface of each level of excavated slope 2 is covered with wire mesh 6 from top to bottom, with one end of the wire mesh 6 fixedly connected to the top of the interlocking anchor piles 3. The wire mesh 6 is a prefabricated wire mesh. This gives the wire mesh 6 strong flexibility, allowing it to be laid close to the slope surface from top to bottom, reducing construction difficulty and cost, and minimizing the risk to personnel setting the wire mesh 6 along the slope. The distance between the end of the wire mesh 6 and the outer edge of the ramp at the bottom of the excavated slope 2 is 0.5m to 1m, further improving the stability of the slope support.

[0029] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 The inner side of the interlocking anchor pile 3 is provided with reinforcing bars 5, and the reinforcing bars 5 are tied to one end of the wire mesh 6. This enhances the overall structural strength of the interlocking anchor pile 3, thereby increasing the connection performance between the wire mesh 6 and the interlocking anchor pile 3, making the support structure more stable and robust when bearing external loads. Temporary shotcrete 4 with a thickness of 5cm to 10cm is installed on the surface of several wire meshes 6. This effectively reinforces the slope, forms a protective layer, prevents external factors such as water flow from damaging the soil, reduces erosion from slope debris flows, and thus improves the stability of the slope. Adjacent temporary shotcrete 4 are overlapped by interlocking anchor piles 3.

[0030] Working principle: Before excavation, firstly, lock anchor piles 3 are installed at the top of the excavated slope 2. The lock anchor piles 3 are 2m away from the excavation opening and are arranged obliquely into the mountain. After the first-stage slope excavation is completed and the ramp of the excavated slope 2 is cleared, steel wire mesh 6 is laid from the top to the outer edge of the ramp at the bottom of the excavated slope 2, 0.5m to 1m away from the edge. The steel wire mesh 6 is firmly connected to the lock anchor piles 3. Then, temporary hanging mesh and shotcrete 4 are sprayed to complete the initial support of the first-stage slope.

[0031] Before the second-level slope excavation, anchor piles 3 are installed along the inner side of the ramp, with the anchor piles 3 angled towards the mountainside. The second-level slope excavation is then carried out. After the second-level slope excavation is completed and the ramp of the excavated slope 2 is cleared, wire mesh 6 is laid along the ramp of the upper-level excavated slope 2 until it reaches the outer edge of the ramp at the bottom of the excavated slope 2, 0.5m to 1m from the edge. The wire mesh 6 is firmly connected to the anchor piles 3 on the inner side of the ramp at the top of the excavated slope 2. Temporary wire mesh and shotcrete 4 are then sprayed to complete the initial support of the second-level slope.

[0032] Repeat the above steps to excavate downwards. This temporary support structure allows for rapid excavation with fewer personnel. The rapid closure not only reduces rainwater intrusion during construction and shortens the time the slope is exposed, but also helps maintain the stability of the slope and reduces the development of unloading relaxation. When the unloading relaxation of the slope further develops, the cracks that appear on the surface of the temporary wire mesh shotcrete can serve as an early warning function, reducing the safety risks of slope excavation and support construction.

[0033] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A temporary support structure for excavating a rock mass slope under heavy unloading, comprising a natural slope (1), several levels of excavated slopes (2), and several interlocking anchor piles (3), wherein the several levels of excavated slopes (2) are located on one side of the natural slope (1), characterized in that: Several of the aforementioned anchor piles (3) are set on the top of the upper excavated slope (2) and on the inner side of the ramp of each level of excavated slope (2). The surfaces of the several levels of excavated slope (2) are all covered with wire mesh (6) from top to bottom, and one end of the wire mesh (6) is fixedly connected to the top of the anchor piles (3). Temporary wire mesh shotcrete (4) is set on the surface of the several wire meshes (6), and two adjacent temporary wire mesh shotcrete (4) overlap each other through the anchor piles (3).

2. The temporary support structure for excavation of a strongly unloaded rock mass slope according to claim 1, characterized in that: The inner side of the lock anchor pile (3) is provided with a reinforcing bar (5), and the reinforcing bar (5) is tied to one end of the wire mesh (6).

3. The temporary support structure for excavation of a strongly unloaded rock mass slope according to claim 1, characterized in that: The thickness of the temporary wire mesh sprayed concrete (4) is 5cm to 10cm.

4. The temporary support structure for excavation of a strongly unloaded rock mass slope according to claim 1, characterized in that: The wire mesh (6) is a finished wire mesh.

5. A temporary support structure for excavation of a strongly unloaded rock mass slope according to claim 1, characterized in that: Several of the aforementioned anchor piles (3) are arranged obliquely into the mountain.

6. The temporary support structure for excavation of a strongly unloaded rock mass slope according to claim 1, characterized in that: The distance between the end of the wire mesh (6) and the outer edge of the bottom of the excavated slope (2) is 0.5m to 1m.

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