阅读说明：本技术 一种巨跨地下洞库三岩柱支撑拆除方法 (Method for dismantling three rock pillar supports of large-span underground cave depot ) 是由 种玉配 刘永胜 姚士磊 刘龙卫 杨效广 宋超业 熊炎林 邵阳 杨朝帅 代昱昊 尚 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种巨跨地下洞库三岩柱支撑拆除方法,包括如下：分划区域：将待开挖地下洞库的工作面分划为上部洞室区和下部洞室区,再将所述上部洞室区在左右方向上分割为三个区,位于上部洞室区左或右边缘处的为边洞区；上部洞室的中部区以及与左或右边洞区相邻的区为岩柱区；相邻的两个岩柱区间的区域为洞区；步骤二、开挖施工：沿隧道开挖方向开挖,确定单次开挖段的距离,依次开挖洞区和边洞区,完成单次开挖段的开挖；沿隧道开挖方向,将各岩柱区分为多个依次相邻的小岩柱；其中,开挖洞区和边洞区的已开挖段,作为该段内待开挖各岩柱区的施工通道。可以保证巨跨地下洞库在岩柱拆除过程中的稳定安全,同时该方法可以实现快速拆除岩柱的目的。(The invention discloses a method for dismantling three rock pillar supports of a large-span underground cave depot, which comprises the following steps: dividing the area: dividing a working face of an underground cave depot to be excavated into an upper cave room area and a lower cave room area, and dividing the upper cave room area into three areas in the left-right direction, wherein the left edge or the right edge of the upper cave room area is a side cave area; the middle area of the upper cavern and the area adjacent to the left or right cavern area are rock pillar areas; the area between two adjacent rock pillars is a hole area; step two, excavation construction: excavating along the excavation direction of the tunnel, determining the distance of a single excavation section, and excavating a tunnel area and a side tunnel area in sequence to finish the excavation of the single excavation section; dividing each rock pillar into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; and the excavated sections of the excavation cave area and the side cave area are used as construction channels of the rock pillar areas to be excavated in the sections. The method can ensure the stability and safety of the huge-span underground cavern in the rock pillar dismantling process, and can achieve the purpose of quickly dismantling the rock pillar.)

1. A method for dismantling three rock pillar supports of a large-span underground cave depot is characterized by comprising the following steps:

step one, dividing an area: dividing a working face of an underground cave depot to be excavated into an upper cave room area and a lower cave room area (4), dividing the upper cave room area into three areas in the left and right direction, and arranging a side cave area (2) at the left edge or the right edge of the upper cave room area; the middle area of the upper cavern and the area adjacent to the left or right cavern area (2) are rock pillar areas (3); the area between two adjacent rock pillar areas (3) is a hole area (1);

step two, excavation construction: excavating along the excavation direction of the tunnel, determining the distance of a single excavation section, sequentially excavating a tunnel region (1) and a side tunnel region (2), and finishing the excavation of the single excavation section;

step three, excavating a rock pillar area (3): dividing each rock pillar area (3) into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; the excavated sections of the excavation cave area (1) and the side cave area (2) are used as construction channels of the rock pillar areas (3) to be excavated in the sections;

constructing each rock pillar area (3) through each construction channel, and only constructing one rock pillar area (3) in one construction channel; during construction, excavating all small rock pillars in sequence until the excavation of the rock pillar region (3) in the excavation section is completed;

step four, sequentially repeating the step one to the step three to finish the excavation of the whole upper cave area;

and step five, finishing the excavation of the lower cavity area (4).

2. The method for dismantling the three rock pillar supports of the huge-span underground cavern as claimed in claim 1, wherein the steps in the third step are as follows: in the same rock pillar zone (3), dividing the small rock pillars into multiple groups which are adjacent in sequence, wherein each group comprises three small rock pillars which are adjacent in sequence; in different said pillar zones (3);

during excavation, small rock pillars are excavated at intervals in the same rock pillar area (3); in different rock pillar areas (3), at any construction time, a small rock pillar on any cross section is in an unfinished state; wherein the cross section refers to a cross section of a small rock pillar in each rock pillar zone (3), and the width of one cross section is the width of one small rock pillar.

3. The method for dismantling the three rock pillar supports of the huge-span underground cavern as claimed in claim 1 or 2, wherein in the second step, when the cavern region (1) and the side cavern region (2) are excavated, radial first anchor cable supports (5) are installed on rock mass above each cavern region, one end of each first anchor cable support (5) is embedded into the upper rock mass of the cavern region (1) and the side cavern region (2), and the other end of each first anchor cable support is embedded into the top wall of the cavern region (1) and the side cavern region (2).

4. The method for dismantling the three rock pillar supports of the huge-span underground cavern as claimed in claim 3, wherein in the fourth step, a second anchor rope support is installed on the rock mass above the small rock pillar to be excavated; when the first section is excavated, one end of the second anchor cable support is embedded into a rock mass above the small rock pillar to be excavated, and the other end of the second anchor cable support is embedded into the top walls of the excavated hole area (1) and the side hole area (2); one end of the second anchor cable support is embedded into a rock mass above the next small rock pillar to be excavated along with the excavation of the small rock pillar, and the other end of the second anchor cable support is embedded into the top wall of the excavated small rock pillar.

Technical Field

The invention belongs to the technical field of engineering construction, and particularly relates to a method for dismantling three rock pillar supports of a large-span underground cave depot.

Background

In the field of underground engineering, large span underground engineering is emerging in various industries. For the huge-span underground engineering, the maximum excavation diameter of an underground cavern is about 20m according to the current design and construction technology. In the excavation process, along with the continuous increase of underground cavern span, corresponding measure need be taken to the in-process, and one mode is, need the support intensity of continuous increase primary branch and two linings, need increase beam column structure simultaneously, realizes reducing the effect of cavern span, but the beam column of increase influences the spatial layout of cavern, influences the result of use. The other mode is that the rock pillar in the reserved cavern is used as a temporary supporting structure of the cavern, and the rock pillar is dismantled after the main space is formed. Because the span of the cavern is large, risks exist in the process of dismantling the rock pillar, and therefore how to dismantle the rock pillar efficiently and safely becomes a problem which needs to be solved urgently at present.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for dismantling three rock pillar supports of a huge-span underground cavern, aiming at overcoming the defects of the prior art, the method can ensure the stability and safety of the huge-span underground cavern in the process of dismantling the rock pillars, and meanwhile, the method can realize the purpose of quickly dismantling the rock pillars.

In order to solve the technical problems, the invention adopts the technical scheme that the method for dismantling the three rock pillar supports of the huge-span underground cavern comprises the following steps:

step one, dividing an area: dividing a working face of an underground cave depot to be excavated into an upper cave room area and a lower cave room area, and dividing the upper cave room area into three areas in the left-right direction, wherein the left edge or the right edge of the upper cave room area is a side cave area; the middle area of the upper cavern and the area adjacent to the left or right cavern area are rock pillar areas; the area between two adjacent rock pillars is a hole area;

step two, excavation construction: excavating along the excavation direction of the tunnel, determining the distance of a single excavation section, and excavating a tunnel area and a side tunnel area in sequence to finish the excavation of the single excavation section;

step three, excavating a rock pillar area: dividing each rock pillar into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; the method comprises the following steps that an excavated section of an excavated cave area and a side cave area is used as a construction channel of each rock pillar area to be excavated in the section;

constructing each rock pillar area by each construction channel, and only constructing one rock pillar area in one construction channel; during construction, excavating all small rock pillars in sequence until the excavation of the rock pillar area in the excavation section is completed;

step four, sequentially repeating the step one to the step three to finish the excavation of the whole upper cave area;

and step five, finishing excavation of the lower cavity area.

Further, in the third step: in the same rock pillar area, dividing the small rock pillars into multiple groups which are adjacent in sequence, wherein each group comprises three small rock pillars which are adjacent in sequence; in different areas of the pillar.

During excavation, in the same rock pillar area, a mode of excavating small rock pillars at intervals is adopted; in different rock pillar areas, at any time of construction, a small rock pillar on any cross section is in an unfinished state; wherein, the cross section refers to the cross section of a small rock pillar in each rock pillar area, and the width of one cross section is the width of one small rock pillar.

Further, in the second step, when the hole area and the side hole area are excavated, radial first anchor cable supports are installed on rock mass above each hole area, one end of each first anchor cable support is embedded into upper rock mass of the excavated hole area and the side hole area, and the other end of each first anchor cable support is embedded into top walls of the excavated hole area and the side hole area.

Further, in the third step, mounting a second anchor cable support on a rock body above the small rock pillar to be excavated; when the first section is excavated, one end of a second anchor cable support is embedded into a rock mass above the small rock pillar to be excavated, and the other end of the second anchor cable support is embedded into the top walls of the excavated hole area and the side hole area; one end of the second anchor cable support is embedded into a rock mass above the next small rock pillar to be excavated along with the excavation of the small rock pillar, and the other end of the second anchor cable support is embedded into the top wall of the excavated small rock pillar.

The invention has the following advantages: 1. the left, middle and right rock pillars are divided at intervals and excavated at intervals, so that small pillars are always present in excavation of any cross section in the huge-span cavern, the rock pillar supporting function is fully exerted, and the stability of the cavern is ensured. 2. After the small rock pillar is excavated at intervals, the anchor cable is adopted for supporting, the anchor cable extends into the top wall of the un-excavated rock pillar, the excavated hole area and the top wall in the side hole area, the rock mass above the excavated rock pillar can be effectively reinforced, and meanwhile, the rock mass above the small rock pillar excavated next time can be pre-reinforced, so that the stability of the cavern is ensured. 3. The rock pillar is divided at intervals and excavated at intervals, so that the rock pillar can be effectively excavated on a plurality of working faces at the same time, and the construction progress is accelerated.

Drawings

FIG. 1 is a sequence diagram of the division and step-by-step excavation of a large-span cavern in the invention;

FIG. 2 is a diagram illustrating the sequence of dividing and removing the left, middle and right rock pillars in this embodiment;

FIG. 3 is a diagram of the excavation of the spacer rock pillar and the anchor cable support in the embodiment;

wherein: 1. a hole area; 2. a side hole area; 3. a rock pillar zone; 4. a lower cavern region, 5, supporting by a first anchor rope; 6. and (6) supporting by using a second anchor cable.

Detailed Description

The invention discloses a method for dismantling three rock pillar supports of a huge-span underground cave depot, wherein the huge-span underground cave depot refers to an underground cave with the span of more than 20. Due to the complexity of underground rock masses, in some areas, the stability of the rock mass is poor, and the possibility of collapse is high when an underground cave depot is excavated.

The method is suitable for the region with relatively poor rock mass stability, which is a huge-span underground cave depot, and comprises the following steps:

step one, dividing an area: dividing a working face of an underground cave depot to be excavated into an upper cave room area and a lower cave room area 4, dividing the upper cave room area into three areas in the left and right direction, and arranging a side cave area 2 at the left edge or the right edge of the upper cave room area; the middle area of the upper cavern and the area adjacent to the left or right cavern area 2 are rock pillar areas 3; the area between two adjacent pillar zones 3 is a cavern zone 1, as shown in fig. 1. When the area is divided, the number and the width of the rock pillar areas 3 are determined by the stability of the rock mass in the area, and are determined according to the hardness and the stability of the rock mass and the prediction of geological conditions in advance. Three pillar zones 3 are set for regions of poor surrounding rock stability.

Step two, excavating a rock pillar area 3: dividing each rock pillar zone 3 into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; the excavated sections of the excavation cave area 1 and the side cave area 2 are used as construction channels of rock pillar areas 3 to be excavated in the sections; constructing each rock pillar zone 3 by each construction channel, and only constructing one rock pillar zone 3 in one construction channel; during construction, the small rock pillars are excavated in sequence until the excavation of the rock pillar area 3 in the excavation section is completed.

In actual construction, only one rock pillar is constructed in one channel, so that the crossing and disorder of personnel and construction are avoided. In the excavation process, in order to further enhance the stability of surrounding rocks and avoid collapse accidents, when the hole area 1 and the side hole area 2 are excavated, radial first anchor cable supports 5 are installed on rock masses above the hole areas, one end of each first anchor cable support 5 is embedded into upper rock masses of the hole area 1 and the side hole area 2, and the other end of each first anchor cable support is embedded into top walls of the excavated hole area 1 and the side hole area 2. The length of the anchor cable is 15-30 m, and the distance is 1.5-3 m.

Constructing each rock pillar zone 3 from the side of each construction channel, and only constructing one rock pillar zone 3 in one construction channel; during construction, the small rock pillars are excavated in sequence until the excavation of the rock pillar area 3 in the excavation section is completed.

When each small rock pillar is excavated, the supporting effect of each small rock pillar needs to be considered, each rock pillar does not exist in an isolated mode, and the three rock pillars jointly play a role in balancing and supporting. Therefore, the following specific scheme is adopted: in the same rock pillar zone 3, the small rock pillars are divided into multiple groups which are adjacent in sequence, and each group comprises three small rock pillars which are adjacent in sequence; in different rock pillar areas 3, the same cross section comprises a small rock pillar in each rock pillar area 3, and the width of the small rock pillar is the width of one small rock pillar; .

When excavating, adopting a mode of excavating small rock pillars at intervals in the same rock pillar area 3; in different rock pillar zones 3, only one small rock pillar on any cross section is in an unfinished state at any time of construction.

Now, the excavation construction process of the small rock pillar is described in detail with reference to fig. 2, fig. 2 shows the state that the excavation of a certain section of the cave region 1 and the side cave region 2 in the underground cavern is completed, the excavation distance of each section is generally 50-60 meters, and the cave region 1 and the side cave region 2 are both used as a channel. The three pillar zones 3 are defined as a left pillar, a middle pillar, and a right pillar, respectively, and the width of the small pillar is generally set to about 5 m. And after division, determining a rock pillar excavation scheme, wherein on the left rock pillar, the three small rock pillars in each group are respectively marked in the axial direction according to the sequence A, B, C, and during initial excavation, the small rock pillar marked as A is selected on the left rock pillar for excavation, so that the small rock pillars marked as A are selected in other two rock pillar areas for excavation. Then the sequence of axially labeling each small rock pillar in each group should be repeated C, A, B on the middle rock pillar, where a is the small rock pillar that was initially excavated, which is staggered with the small rock pillar on the left rock pillar. In the right rock pillar, the order of marking of the small rock pillars in each group should be repeated in the order of B, C, A, and a in the right rock pillar is the small rock pillar that was originally excavated. Thus, when excavating, at least one small rock pillar exists on a cross section at any time. The supporting function of the rock pillar is fully exerted, and the stability of the cavern is ensured.

When excavating the small rock pillar marked as A, performing anchor cable support on A, and installing a second anchor cable support on a rock mass above the small rock pillar A to be excavated as shown in figure 3; when the first section is excavated, one end of a second anchor cable support is embedded into a rock mass above the small rock pillar A to be excavated, and the other end of the second anchor cable support is embedded into the top walls of the excavated hole area 1 and the side hole area 2; along with the excavation of the small rock pillar A, one end of a second anchor cable support is embedded into a rock mass above the next small rock pillar to be excavated, and the other end of the second anchor cable support is embedded into an anchor cable on the top wall of the excavated small rock pillar, wherein the length of the anchor cable is 15-30 m, and the distance between the anchor cables is 2.5 m. Therefore, the rock mass above the excavated rock pillar can be effectively reinforced, and the rock mass above the excavated rock pillar next time can be pre-reinforced, so that the stability of the cavern is ensured.

Step four, sequentially repeating the step one to the step three to finish the excavation of the whole upper cave area;

and step five, after the excavation of the upper cave room area is finished, constructing the lower cave room area 4, and finishing the excavation of the lower cave room area 4.

According to the method for dismantling the three rock pillar supports of the huge-span underground cave depot, three rock pillar areas 3 which are arranged at intervals are divided for the easily collapsed rock mass according to different rock mass stability, one rock pillar area 3 is arranged at the central axis of the cave depot, the other two rock pillar areas are arranged on two sides of the central axis, and after the cave area 1 and the side cave area 2 are excavated, the three rock pillar areas 3 play a supporting role in the excavation process of the cave area 1 and the side cave area 2 and after the excavation. When each rock pillar area 3 is dismantled, each rock pillar area 3 is divided into a plurality of small rock pillars along the tunnel excavation direction, and during excavation, the small rock pillar areas are excavated in an interval excavation mode, so that at least one small rock pillar is ensured in an excavation section, and in the excavation process, the cavern is always in a state supported by the small rock pillars, and the stability of the cavern is ensured. And when excavating the little pillar, can be under construction at a plurality of working faces simultaneously, be favorable to accelerating the construction progress.