阅读说明：本技术 一种高速铁路大断面隧道快速施工方法 (Rapid construction method for large-section tunnel of high-speed railway ) 是由 戴长云 谢秉军 柯松林 郑玉明 江新明 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种高速铁路大断面隧道快速施工方法采用三台阶同步施工的方法,优化了高速铁路软弱围岩隧道开挖工法,不需要进行临时支护,有利于降低施工成本,并进一步优化工序安排,达到减小围岩变形,提高软弱围岩隧道稳定性,从而保障隧道施工安全,提高软弱围岩隧道施工效率的目的。(The invention discloses a rapid construction method of a high-speed railway large-section tunnel, which adopts a three-step synchronous construction method, optimizes the excavation construction method of a high-speed railway weak surrounding rock tunnel, does not need temporary support, is favorable for reducing the construction cost, further optimizes the process arrangement, and achieves the purposes of reducing the surrounding rock deformation and improving the stability of the weak surrounding rock tunnel, thereby ensuring the tunnel construction safety and improving the construction efficiency of the weak surrounding rock tunnel.)

1. A rapid construction method for a large-section tunnel of a high-speed railway is characterized by comprising the following steps:

s1, judging the stability of the tunnel surrounding rock;

s2, synchronously excavating an upper step (10), a middle step (11) and a lower step (12) in the tunnel;

s3, synchronously deslagging the upper step (10), the middle step (11) and the lower step (12);

s4, sequentially installing first arch centering on the upper step (10), the middle step (11) and the lower step (12), and sequentially performing supporting construction measures on the first arch centering;

s5, excavating an inverted arch primary support (13) synchronously with S4, wherein the inverted arch primary support (13) is spaced from the lower step (12), and deslagging and installing a second arch frame are sequentially performed after the inverted arch primary support (13) is excavated;

s6, sequentially spraying concrete to the second arch centering and each first arch centering;

s7: and repeating the construction sequence from S1 to S6 until the construction of the tunnel is completed.

2. The rapid construction method of the high-speed railway large-section tunnel according to claim 1, characterized in that: and determining an excavation mode according to the judgment of the surrounding rock, wherein the excavation mode comprises mechanical excavation and blasting excavation.

3. The rapid construction method of the high-speed railway large-section tunnel according to claim 1, characterized in that: the height of the upper step (10), the height of the middle step (11) and the height of the lower step (12) are respectively 4.5m, 3.6m and 2.9m, the length of the upper step (10) is 5-8 m, and the length of the middle step (11) is 5 m.

4. The rapid construction method of the high-speed railway large-section tunnel according to claim 3, characterized in that: the diameter of the primary inverted arch support (13) is not more than twice of the hole diameter of the tunnel.

5. The rapid construction method of the high-speed railway large-section tunnel according to claim 4, characterized in that: the horizontal distance between the primary inverted arch support (13) and the tunnel face is not more than twice of the tunnel diameter of the tunnel.

6. The rapid construction method of the high-speed railway large-section tunnel according to claim 5, characterized in that: in synchronism with steps S4 and S5, an inverted arch bridge (14) is set, the net span of the inverted arch bridge (14) being 24 m.

7. The rapid construction method of the high-speed railway large-section tunnel according to claim 1, characterized in that: the support construction measures comprise installation of a lock pin steel pipe and an anchor rod.

8. The rapid construction method of the high-speed railway large-section tunnel according to claim 1, characterized in that: the total construction time of the upper step (10), the middle step (11) and the lower step (12) is 16-18 h.

9. The rapid construction method of the high-speed railway large-section tunnel according to claim 8, characterized in that: the total construction time of the primary inverted arch support (13) is 7-8 h.

10. The rapid construction method of the high-speed railway large-section tunnel according to claim 9, characterized in that: the total construction time period of S1 to S6 is 20 h.

Technical Field

The invention relates to the field of tunnel construction, in particular to a rapid construction method for a large-section tunnel of a high-speed railway.

Background

At present, the construction of weak surrounding rock tunnels in China generally takes a small-section multi-step excavation process such as a step method, a cross mid-partition method, a double-side-wall pit guiding method and the like as a main process, the operation space is small, a large number of temporary supports exist, repeated installation and removal are needed, the construction progress is reduced, the continuous operation of mechanical equipment is not facilitated, the mechanical construction supporting equipment of the tunnels cannot form continuous operation under the influence of the unevenness of surrounding rock sections of the tunnels, and the work efficiency of the mechanical equipment is reduced. The weak surrounding rock tunnel has softer rock quality, joint crack development, low bearing capacity and easy deformation, according to the deformation characteristics of the weak surrounding rock, the supporting measures of the tunnel, the current technical levels of construction process, construction method, machinery and the like, the method should firstly study how to carry out fast excavation, fast support and fast sealing on the construction method, the creep characteristic of the weak surrounding rock enables the deformation duration to be long, and if the construction speed is slow, the time for supporting and sealing to form a ring is long, large deformation is easy to occur, even the transition is loose and collapse is easy to occur. Therefore, the rapid sealing and looping is a basic requirement for improving the stability of the weak surrounding rock tunnel and is also the most fundamental strategy for the construction of the weak surrounding rock tunnel.

The selection of the height and the length of the steps in the step method has great influence on the work efficiency. Too high steps have too long ballast raking time and poor stability, and too low steps have limited mechanical operation space; the step is too long and difficult to remove the slag, which is not beneficial to the parallel operation, the step is too short and the rack is unstable, and the driller is inconvenient to operate.

Disclosure of Invention

The invention aims to solve at least one of the technical problems in the prior art, and provides a rapid construction method for a large-section tunnel of a high-speed railway, which can reduce surrounding rock deformation and improve the stability of a weak surrounding rock tunnel, thereby ensuring the safety of tunnel construction and improving the construction efficiency of the weak surrounding rock tunnel.

According to the embodiment of the first aspect of the invention, a rapid construction method for a large-section tunnel of a high-speed railway is provided, which comprises the following steps:

s1, judging the stability of the tunnel surrounding rock;

s2, synchronously excavating an upper step, a middle step and a lower step in the tunnel;

s3, synchronously deslagging the upper step, the middle step and the lower step;

s4, sequentially installing first arch centers for the upper step, the middle step and the lower step, and sequentially performing supporting construction measures on the first arch centers;

s5, synchronously performing excavation on an inverted arch primary support, wherein the inverted arch primary support is separated from a lower step, and sequentially performing deslagging and second arch frame installation operations after the inverted arch primary support is excavated;

s6, spraying concrete to the second arch centering and each first arch centering in sequence;

s7: and repeating the construction sequence from S1 to S6 until the construction of the tunnel is completed.

Has the advantages that: the rapid construction method for the high-speed railway large-section tunnel optimizes the excavation construction method for the high-speed railway weak surrounding rock tunnel, does not need temporary support, is favorable for reducing the construction cost, further optimizes the process arrangement, and achieves the purposes of reducing the surrounding rock deformation and improving the stability of the weak surrounding rock tunnel, thereby ensuring the tunnel construction safety and improving the construction efficiency of the weak surrounding rock tunnel.

According to the rapid construction method of the high-speed railway large-section tunnel, the excavation mode is determined according to the judgment of the surrounding rock, the excavation mode comprises mechanical excavation and blasting excavation, the deformation of the surrounding rock is controlled to the maximum extent, and the stability of the surrounding rock is ensured.

According to the rapid construction method of the high-speed railway large-section tunnel, the heights of the upper step, the middle step and the lower step are respectively 4.5m, 3.6m and 2.9m, the length of the upper step is 5-8 m, the length of the middle step is 5m, and basic parameters of a three-step excavation method are finally determined by combining the stability of surrounding rocks, the operation cooperativity, the tool feasibility, the equipment matching property and the like according to the characteristics of weak surrounding rocks.

According to the rapid construction method of the high-speed railway large-section tunnel, the diameter of the primary support of the inverted arch is not more than twice of the hole diameter of the tunnel, the ring is closed in time, and the full-ring closing time of the primary support is shortened.

According to the rapid construction method of the high-speed railway large-section tunnel, disclosed by the embodiment of the first aspect of the invention, the horizontal distance between the primary inverted arch support and the tunnel face is not more than twice of the tunnel diameter, the number of people on the tunnel face can be dispersed, the number of people on the tunnel face is reduced, and the risk is reduced.

According to the rapid construction method of the high-speed railway large-section tunnel, which is disclosed by the embodiment of the first aspect of the invention, the steps S4 and S5 are performed synchronously, and the inverted arch trestle is arranged, wherein the net span of the inverted arch trestle is 24 m.

According to the rapid construction method of the high-speed railway large-section tunnel, support construction measures comprise installation of the locking leg steel pipe and the anchor rod.

According to the rapid construction method of the high-speed railway large-section tunnel, the total construction time of the upper step, the middle step and the lower step is 16-18 hours, and parallel operation is fully performed.

According to the rapid construction method of the high-speed railway large-section tunnel, the total construction time of the primary inverted arch support is 7-8 hours, and zero clearance of the working procedure is guaranteed.

According to the rapid construction method of the high-speed railway large-section tunnel, disclosed by the embodiment of the first aspect of the invention, the total construction time from S1 to S6 is 20h, and the construction period is shortened.

Drawings

In order to more clearly illustrate the technical solution in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is clear that the described figures are only some embodiments of the invention, not all embodiments, and that a person skilled in the art can also derive other designs and figures from them without inventive effort.

FIG. 1 is a schematic diagram of construction conditions of an embodiment of the invention;

fig. 2 is a schematic view of a tunnel excavation step in an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.