阅读说明：本技术 一种巨跨地下洞库双岩柱支撑拆除方法 (Method for dismantling double-rock-pillar support of huge-span underground cave depot ) 是由 洪开荣 种玉配 刘永胜 卓越 刘龙卫 姚士磊 杨效广 熊炎林 邵阳 杨朝帅 代昱 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双岩柱支撑拆除方法,该方法如下：将待开挖地下洞库的工作面分划为上部洞室和下部洞室,再将上部洞室沿左右方向分为三个区域,位于左或右边缘处的为边洞,处于中部的为中洞,位于左或右边洞和中洞间的区域为左或右岩柱。沿隧道开挖方向开挖,确定单次开挖段的距离,然后顺次开挖中洞和边洞,完成单次开挖段的开挖。沿隧道开挖方向,将两个岩柱分为多个依次相邻的小岩柱；且在开挖时,同一岩柱,采取间隔开挖小岩柱的方式；其中,已开挖段的中洞和边洞作为各岩柱的开挖通道。通过该方法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 double rock pillar supports of a large-span underground cave depot, which comprises the following steps: dividing a working face of an underground cave depot to be excavated into an upper cave chamber and a lower cave chamber, dividing the upper cave chamber into three regions along the left and right directions, wherein the left or right edge is a side cave, the middle part is a middle cave, and the region between the left or right cave and the middle cave is a left or right rock pillar. And excavating along the tunnel excavation direction, determining the distance of the single excavation section, and then excavating the middle hole and the side hole in sequence to finish the excavation of the single excavation section. Dividing the two rock pillars into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; when excavating, the same rock pillar adopts a mode of excavating small rock pillars at intervals; wherein, the middle hole and the side hole of the excavated section are used as the excavation channel of each rock pillar. The method can ensure the stability and safety of the huge-span underground cavern in the rock pillar dismantling process, and can realize the purpose of quickly dismantling the rock pillar.)

1. A method for dismantling double 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 chamber and a lower cave chamber (4), dividing the upper cave chamber into three regions along the left and right directions, wherein the left or right edge is provided with a side cave (2), the middle cave (1) is arranged in the middle, and the region between the left or right cave (2) and the middle cave (1) is provided with a left or right rock pillar (3);

step two, excavation construction: excavating along the excavation direction of the tunnel, determining the distance of a single excavation section, and then excavating a middle tunnel (1) and a side tunnel (2) in sequence to finish the excavation of the single excavation section;

step three, excavating a rock pillar (3): dividing the two rock pillars (3) into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; excavating a rock pillar (3) on one side opposite to the excavated cave region (1) or the side cave (2); on the same rock pillar (3), dividing the small rock pillars into multiple groups which are adjacent in sequence, wherein each group comprises two adjacent small rock pillars; when excavating, the same rock pillar (3) adopts a mode of excavating small rock pillars at intervals; wherein, the middle hole (1) and the side hole (2) of the excavated section are used as the excavation channel of each rock pillar (3);

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 (4).

2. The method for dismantling the double rock pillar supports of the huge-span underground cavern as claimed in claim 1, wherein in the third step, at any time of construction, a small rock pillar on any cross section is in an unfinished state; wherein: the same cross section is a cross section containing one small rock pillar in the left rock pillar and the right rock pillar (3), and the width of the cross section is the width of one small rock pillar.

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

4. The method for dismantling the double rock pillar supports of the huge-span underground cavern as claimed in claim 3, wherein in the third 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 (6) 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 underground engineering construction, and particularly relates to a method for dismantling a double-rock-pillar support of a large-span underground cave depot.

Background

In the field of underground engineering, large span underground engineering is emerging in various industries. At present, the research and experience of huge underground engineering have some defects. According to the current design and construction technology, the maximum excavation diameter of the underground cavern is about 20 m. Along with the continuous increase of underground cavern span, need constantly increase the support intensity of just propping up and two linings, need increase some beam column structures simultaneously, realize reducing the effect of cavern span, but the beam column of increase influences the spatial layout of cavern, influences the result of use. The rock pillar in the reserved cavern can be used as a temporary supporting structure of the cavern, and the rock pillar is detached 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 the dual rock pillar supports of the huge-span underground cavern, aiming at overcoming the defects of the prior art, so that the method can ensure the stability and safety of the huge-span underground cavern in the process of dismantling the rock pillars, and 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 double 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 chamber and a lower cave chamber, dividing the upper cave chamber into three regions along the left and right directions, wherein the left or right edge is a side cave, the middle part is a middle cave, and the region between the left or right cave and the middle cave is a left or right rock pillar.

Step two, excavation construction: and excavating along the tunnel excavation direction, determining the distance of the single excavation section, and then excavating the middle hole and the side hole in sequence to finish the excavation of the single excavation section.

Step three, excavating rock pillars: dividing the two rock pillars into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; excavating a rock pillar on one side in an excavated hole area or side hole; on the same rock pillar, dividing the small rock pillars into a plurality of groups which are adjacent in sequence, wherein each group comprises two adjacent small rock pillars; when excavating, the same rock pillar adopts a mode of excavating small rock pillars at intervals; wherein, the middle hole and the side hole of the excavated section are used as the excavation channel of each rock pillar.

And 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.

Furthermore, in the third step, at any time of construction, a small rock pillar on any cross section is in an unfinished state; wherein: the same cross section is a cross section containing a small rock pillar in the left rock pillar and the right rock pillar respectively, and the width of the cross section is the width of one small rock pillar.

Furthermore, when middle holes and side holes are excavated, radial first anchor cable supports are installed on rock masses above the holes, one ends of the first anchor cable supports are embedded into upper rock masses of the excavated hole area and the side hole area, and the other ends of the first anchor cable supports are 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; along with the excavation of the small rock pillar, one end of the 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 the top wall of the excavated small rock pillar.

The invention has the following advantages: 1. the left and right rock pillars are divided at intervals and excavated at intervals, so that the rock pillars are always arranged in the transverse section of the huge-span cavern, the supporting effect of the rock pillars is fully exerted, and the stability of the cavern is ensured.

2. After the small rock pillars are excavated at intervals, the anchor cables are adopted for supporting, the anchor cables stretch into the upper parts of the un-excavated rock pillars and the upper parts of the excavated middle holes and the left and right holes, so that rock masses above the excavated rock pillars can be effectively reinforced, and meanwhile, the rock masses above the excavated rock pillars next time can be pre-reinforced, and the stability of a 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; (ii) a

FIG. 2 is a diagram illustrating a sequence of dividing and dismantling left and right rock pillars in this embodiment;

FIG. 3 is a diagram of alternate pillar excavation and anchor cable support;

wherein: 1. a middle hole; 2. a side hole; 3. a rock pillar; 4. a lower cavern; 5. supporting a first anchor cable; 6. and (5) supporting by two anchor cables.

Detailed Description

The invention discloses a method for excavating a huge-span underground cave depot and dismantling a double-rock pillar support, wherein the huge-span underground cave depot refers to an underground cave with the span of more than 20 meters. In this embodiment, the stability of the rock mass is relatively high, so a double-pillar support method is adopted.

The invention discloses a method for excavating a huge-span underground cave depot and dismantling double rock pillar supports, which 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 chamber and a lower cave chamber 4, dividing the upper cave chamber into three regions along the left and right directions, wherein the left or right edge is provided with a side cave 2, the middle part is provided with a middle cave 1, and the region between the left or right cave 2 and the middle cave 1 is provided with a left or right rock pillar 3; as shown in fig. 1. The number and width of the rock pillars 3 are determined according to the stability of the rock mass in the region. The width of the rock mass is not particularly strictly limited, and although the stability of the rock mass needs to be considered, the width of the rock mass still needs to be determined according to actual conditions, such as hardness of the rock mass and complexity of surrounding terrain.

Step two, excavation construction: excavating along the excavation direction of the tunnel, determining the distance of a single excavation section, and then excavating a middle tunnel 1 and a side tunnel 2 in sequence to finish the excavation of the single excavation section; the middle hole 1 and the side hole 2 of the excavated sections are used as excavation channels of the rock pillars 3.

Step three, excavating a rock pillar 3: dividing the two rock pillars 3 into a plurality of small rock pillars which are adjacent in sequence along the tunnel excavation direction; excavating a rock pillar 3 on one side in the excavated hole area 1 or the side hole 2; on the same rock pillar 3, dividing the small rock pillars into a plurality of groups which are adjacent in sequence, wherein each group comprises two adjacent small rock pillars; when excavating, the same rock pillar 3 adopts a mode of excavating small rock pillars at intervals; wherein, the middle hole 1 and the side hole 2 of the excavated section are used as the excavation channel of each rock pillar 3. At any time of construction, a small rock pillar is in an unfinished state on any cross section; wherein: the same cross section is a cross section containing a small rock pillar in each of the left and right rock pillars 3, and the width of the cross section is the width of one small rock pillar.

When a middle hole 1 and a side hole 2 are excavated, radial first anchor cable supports 5 are installed on rock mass above each hole area, one end of each first anchor cable support 5 is embedded into the upper rock mass of the excavated hole area 1 and the side hole area 2, and the other end of each first anchor cable support is embedded into the top walls of the excavated hole area 1 and the side hole area 2.

In the third step, a second anchor cable support is arranged 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 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.

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 chamber 4.

The excavation construction process of the small rock pillars is described in detail with reference to fig. 2, fig. 2 shows the state that a certain section of side cave 2 and a middle cave 1 in an underground cavern are excavated, the excavation distance of each section is generally 50-60 meters, the excavated section of side cave 2 and the middle cave 1 are used as channels, two rock pillars 3 are respectively set as a left rock pillar and a right rock pillar, and each rock pillar is divided into a plurality of small rock pillars which are adjacent in sequence along the axial direction, and the two small rock pillars are in a group. The width of the small pillar is generally set to about 5 m. And after division, determining a rock pillar excavation scheme, marking two small rock pillars in each group on the left rock pillar respectively according to the sequence of B, A along the axial direction, and during initial excavation, selecting the small rock pillar marked as A on the left rock pillar for excavation, so that the small rock pillar marked as A is selected from each group of small rock pillars of the left rock pillar for excavation. On the right rock pillar, the excavation position is to be staggered with the excavation position on the left rock pillar, so in the right rock pillar, the marking sequence of the small rock pillars in each group should be A, B, and a in the right rock pillar is the small rock pillar excavated for the first time. And during excavation, excavating the small rock pillars A on the rock pillars at the same time. After the small rock pillar A is excavated, the small rock pillars B in each group are excavated in sequence according to the mode. The excavation of the section of internal rock column 3 is completed.

According to the method for excavating the huge-span underground cave depot and dismantling the double rock pillar supports, the left rock pillar 3 and the right rock pillar 3 which are arranged at intervals are divided aiming at the region with better rock mass stability, and the two rock pillars 3 play a supporting role in the excavation process of the side cave 2 and the middle cave 1 and after excavation. When each rock pillar 3 is dismantled, each rock pillar 3 is divided into a plurality of small rock pillars along the tunnel excavation direction, and during excavation, the small rock pillars 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, so that 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.