阅读说明：本技术 一种测量软硬复合地层掌子面稳定性的实验方法与装置 (Experimental method and device for measuring stability of soft and hard composite stratum face ) 是由 王松 孟昭晖 郭水 李柏青 杨建辉 王建 郭奇峰 许凯 张斌 王超 王森 孟兴 于 2020-05-28 设计创作，主要内容包括：本发明涉及一种测量软硬复合地层掌子面稳定性的实验装置及方法,其中,透明观察板(2)与有凹槽的的模型框体(1)形成模型箱体；模型框体(1)上设有与半隧道形门(3)配合的半隧道形开口；抽拉槽(4)能通过半隧道形开口插入模型箱体中。实验时,将配置好的软硬土试样加入模型箱体内；打开半隧道形门开挖形成土槽；将抽拉槽(4)从半隧道形门(3)进入伸入土槽,在土体稳定后记录土体掌子面休止角；如此直至硬土层在掌子面不同位置的软硬土试样遍历完,根据得到的最小掌子面休止角确定出地层最为稳定时较硬土层位于掌子面的位置。本发明能很好地模拟软硬复合地层条件下隧道开挖过程,可确定在已知确定的地层条件下掌子面稳定程度。(The invention relates to an experimental device and a method for measuring the stability of a soft and hard composite stratum tunnel face, wherein a transparent observation plate (2) and a model frame body (1) with a groove form a model box body; a half tunnel-shaped opening matched with the half tunnel-shaped door (3) is arranged on the model frame body (1); the drawing groove (4) can be inserted into the model box body through the half-tunnel-shaped opening. During the experiment, the prepared soft and hard soil sample is added into the model box body; opening a half tunnel-shaped door to form a soil groove; the drawing groove (4) enters the soil groove from the half-tunnel-shaped door (3) and records the angle of repose of the soil body tunnel face after the soil body is stabilized; and determining the position of the harder soil layer on the tunnel face when the stratum is most stable according to the obtained minimum tunnel face repose angle until the soft soil and hard soil samples of the hard soil layer at different positions on the tunnel face are traversed. The method can well simulate the tunnel excavation process under the soft and hard composite stratum condition, and can determine the stability degree of the tunnel face under the known and determined stratum condition.)

1. The utility model provides a measure experimental apparatus of soft or hard composite stratum face stability which characterized in that, experimental apparatus include:

the model comprises a model frame body (1), a transparent observation plate (2), a semi-tunnel-shaped door (3) and a drawing groove (4);

the model frame body (1) comprises a bottom plate, a first side plate, a second side plate and a rear plate, wherein the first side plate, the second side plate and the rear plate are respectively fixed with three sides of the bottom plate and are vertically connected; the bottom plate, the first side plate and the second side plate are respectively provided with corresponding grooves at the front ends thereof;

two sides of the transparent observation plate (2) are respectively embedded in the grooves of the first side plate and the second side plate, and the bottom of the transparent observation plate is embedded in the prefabricated groove of the bottom plate to form a model box body;

a first side plate and/or a second side plate of the model frame body (1) are/is provided with a half-tunnel-shaped opening matched with the half-tunnel-shaped door (3) in close contact with the groove part; the half-tunnel-shaped door (3) can be inserted into the model box body from the half-tunnel-shaped opening;

the drawing groove (4) is a half-tunnel-shaped arc-shaped structure body, and the drawing groove (4) can be inserted into the model box body through the half-tunnel-shaped opening.

2. The experimental device for measuring the stability of the palm surface of the soft and hard composite stratum according to claim 1, wherein grid lines with fixed intervals are marked on the transparent observation plate (2).

3. The experimental device for measuring the stability of the soft and hard composite stratum tunnel face as claimed in claim 1, wherein the drawing groove (4) comprises a semi-tunnel-shaped arc-shaped structure inner body and a semi-tunnel-shaped arc-shaped structure outer body which are nested together.

4. The experimental device for measuring the stability of the soft and hard composite stratum tunnel face according to claim 1, wherein the drawing groove (4) comprises a semi-tunnel-shaped arc-shaped structure outer body.

5. An experimental method for measuring the stability of the hard-soft composite stratum tunnel face by using the experimental device for measuring the stability of the hard-soft composite stratum tunnel face of any one of claims 1 to 4, wherein the experimental method comprises the following steps:

s101, inserting a transparent observation plate (2) into a groove of a model frame body (1) and fixing the transparent observation plate, and closing a half-tunnel-shaped door (3) to form a model box body;

step S102, adding a prepared soft and hard soil sample into a model box according to the position requirement of a hard soil layer on a tunnel face; compacting and leveling each layer of soft and hard soil sample soil body when being added;

step S103, after the last soil body is compacted and leveled, standing to enable the internal stress of the soil body to be automatically balanced;

step S104, opening the half-tunnel-shaped door (3), and excavating inwards along the half-tunnel-shaped opening to form a first part of soil groove; the drawing groove (4) enters from the half-tunnel-shaped door (3), the drawing groove (4) extends inwards along the soil tank, and the extending length is recorded as a first length;

s105, with the soil in the model box body flowing in parallel, discharging the flowing partial soil from the drawing groove (4), observing the tunnel face deformation condition and time of the soil in the model box body from the transparent observation plate (2), and recording the tunnel face repose angle of the soil in the model box body after the deformation is stable;

step S106, judging whether the preset excavation length is reached, if not, executing step S107, namely, continuing to excavate inwards to form a second part soil groove; continuously extending the drawing groove (4) inwards along the soil groove; then returning to step S105; if yes, go to step S108;

step S108, judging whether the hard soil samples at different positions of the tunnel face of the hard soil layer are traversed completely, if not, executing step S109; if the traversal is completed, executing step S110;

step S109, emptying the model box body, selecting a soft soil sample and a hard soil sample which are arranged on the next position of the tunnel face of the hard soil layer, and returning to the step S101;

and S110, selecting a minimum face repose angle from the recorded face repose angles, and determining the position of a harder soil layer on the face when the stratum is most stable according to the minimum face repose angle.

6. The experimental method for measuring soft-hard composite stratum tunnel face stability according to claim 5, is characterized in that the experimental method further comprises the following steps:

and preparing a plurality of soft and hard soil samples according to the position requirement of the hard soil layer on the tunnel face.

7. The experimental method for measuring the stability of the hard and soft composite formation tunnel face of claim 5, wherein the process of extending the drawing groove (4) inwards along the soil groove in step S104 or step S106 comprises:

and the outer body of the semi-tunnel-shaped arc structure in the drawing groove (4) extends into the soil groove, so that the outer body of the semi-tunnel-shaped arc structure forms a primary support structure for the soil body in the whole model box body.

8. The experimental method for measuring the stability of the hard and soft composite formation tunnel face of claim 5, wherein the process of extending the drawing groove (4) inwards along the soil groove in step S104 or step S106 comprises:

after the semi-tunnel-shaped arc-shaped structure outer body of the drawing groove (4) extends to a first length, the semi-tunnel-shaped arc-shaped structure inner body of the drawing groove (4) clings to the semi-tunnel-shaped arc-shaped structure outer body and extends to a set length which does not exceed the first length; so that the semi-tunnel-shaped arc-shaped structure inner body and the semi-tunnel-shaped arc-shaped structure outer body of the drawing groove (4) form a secondary lining structure of the soil body in the whole model box body.

Technical Field

The invention relates to the technical field of tunnel engineering, in particular to an experimental method and device for measuring the stability of a soft-hard composite stratum tunnel face, and belongs to model tests.

Background

The rapid development of cities promotes the large development of underground spaces, the stratum conditions are complicated and complicated, the underground spaces cannot be fully reflected in geological exploration, the stratum conditions are not fully considered, the construction is not troublesome, the engineering progress is slow, and the construction difficulty is high. Many factors are usually considered in the design of the tunnel position, other factors are not considered, a good geological condition is selected to reduce the construction difficulty and accelerate the construction pace, so that the geological condition is very important in the line selection process.

The disturbance of tunnel excavation to surrounding rock is three-dimensional, and the displacement deformation of tunnel face is also very important, and with the level of domestic tunnel engineering mechanization constantly improves, people also tend gradually to excavate into full-face excavation from many steps branch excavation, this has proposed higher requirement to face stability.

The underground soil layer has relative soft soil layer and hard soil layer, and common mostly is soft under the hard, and other factors such as circuit, station, existing structure control are many in face position this moment, and when there was hard soil layer in the middle of the soft soil layer in the geological condition, harder soil layer can strengthen face stability, and the face is the most stable when harder soil layer was located at which position of face, and this position is worth discussing to need to verify through the experiment.

Disclosure of Invention

The invention aims to provide an experimental method and device for measuring the stability of a hard-soft composite stratum face, aiming at the technical problems in the prior art, which can well simulate the tunnel excavation process under the hard-soft composite stratum condition, determine the stability degree of the face under the known and determined stratum condition, provide experimental basis for design and constructors, and select a proper position to arrange the face.

The purpose of the invention is realized by the following technical scheme:

the invention provides an experimental device for measuring the stability of a soft and hard composite stratum face, which comprises:

the model comprises a model frame body, a transparent observation plate, a semi-tunnel-shaped door and a drawing groove;

the model frame body comprises a bottom plate, a first side plate, a second side plate and a rear plate, wherein the first side plate, the second side plate and the rear plate are respectively fixed on three sides of the bottom plate and are vertically connected; the bottom plate, the first side plate and the second side plate are respectively provided with corresponding grooves at the front ends thereof;

the two sides of the transparent observation plate are respectively embedded in the grooves of the first side plate and the second side plate, and the bottom of the transparent observation plate is embedded in the prefabricated groove of the bottom plate to form a model box body;

a first side plate and/or a second side plate of the model frame body are/is provided with a half-tunnel-shaped opening matched with the half-tunnel-shaped door in close contact with the groove part; the half tunnel-shaped door can be inserted into the model box body from the half tunnel-shaped opening;

the drawing groove is a semi-tunnel-shaped arc-shaped structure body, and can be inserted into the model box body through the semi-tunnel-shaped opening.

More preferably, the transparent viewing plate is marked with grid lines at fixed intervals.

More preferably, the drawing groove comprises a half tunnel-shaped arc-shaped structure inner body and a half tunnel-shaped arc-shaped structure outer body which are nested together.

More preferably, the drawing groove comprises a half-tunnel-shaped arc-shaped structure outer body.

The invention also provides an experimental method for measuring the stability of the hard-soft composite stratum face, which comprises the following steps:

s101, inserting a transparent observation plate into a groove of a model frame body, fixing the transparent observation plate, and closing a half-tunnel-shaped door to form a model box body;

step S102, adding a prepared soft and hard soil sample into a model box according to the position requirement of a hard soil layer on a tunnel face; compacting and leveling each layer of soft and hard soil sample soil body when being added;

step S103, after the last soil body is compacted and leveled, standing to enable the internal stress of the soil body to be automatically balanced;

step S104, opening the semi-tunnel-shaped door, and excavating inwards along the semi-tunnel-shaped opening to form a first part of soil tank; the drawing groove enters from the half-tunnel-shaped door, the drawing groove inwards extends along the soil groove, and the extending length is recorded as a first length;

step S105, along with the soil in the model box body flowing in parallel, discharging the flowing partial soil from the drawing groove, observing the tunnel face deformation condition and time of the soil in the model box body from the transparent observation plate, and recording the tunnel face repose angle of the soil in the model box body after the deformation is stable;

step S106, judging whether the preset excavation length is reached, if not, executing step S107, namely, continuing to excavate inwards to form a second part soil groove; continuously extending the drawing groove inwards along the soil groove; then returning to step S105; if yes, go to step S108;

step S108, judging whether the hard soil samples at different positions of the tunnel face of the hard soil layer are traversed completely, if not, executing step S109; if the traversal is completed, executing step S110;

step S109, emptying the model box body, selecting a soft soil sample and a hard soil sample which are arranged on the next position of the tunnel face of the hard soil layer, and returning to the step S101;

and S110, selecting a minimum face repose angle from the recorded face repose angles, and determining the position of a harder soil layer on the face when the stratum is most stable according to the minimum face repose angle.

More preferably, the experimental method further comprises:

and preparing a plurality of soft and hard soil samples according to the position requirement of the hard soil layer on the tunnel face.

More preferably, the process of extending the drawing groove inwards along the soil groove in step S104 or step S106 includes:

and stretching the outer body of the semi-tunnel-shaped arc structure in the drawing groove into the soil groove, so that the outer body of the semi-tunnel-shaped arc structure forms a primary support structure for the soil body in the whole model box body.

More preferably, the process of extending the drawing groove inwards along the soil groove in step S104 or step S106 includes:

after the semi-tunnel-shaped arc-shaped structure outer body of the drawing groove extends to a first length, the semi-tunnel-shaped arc-shaped structure inner body of the drawing groove clings to the semi-tunnel-shaped arc-shaped structure outer body and extends to a set length which does not exceed the first length; so that the inner body of the semi-tunnel-shaped arc structure of the drawing groove and the outer body of the semi-tunnel-shaped arc structure form a secondary lining structure of the soil body in the whole model box.

Compared with the prior art, the technical scheme of the invention has the following technical effects:

according to the invention, through the experimental device for measuring the stability of the tunnel face of the soft and hard composite stratum, the tunnel excavation process under the condition of the soft and hard composite stratum can be well simulated, and most of stratum conditions with an interlayer can be simulated by adjusting the thickness of the soil layer. The invention has simple structure and convenient operation.

The invention can determine the stability degree of the face under the known and determined stratum conditions by simulating the position of the face through an experimental method for measuring the stability of the soft-hard composite stratum face, provides experimental basis for design and constructors, selects a proper position to arrange the face, reduces the occurrence of engineering problems from the design angle, can improve the stability of the face in actual construction, forms a self-stabilizing structure as much as possible, reduces the displacement of the face, can improve the safety level, reduces the use of supporting measures, reduces the manufacturing cost and greatly improves the engineering quality.

Drawings

FIG. 1 is an exploded view of the experimental set-up according to the present invention.

FIG. 2 is a schematic structural view of the experimental apparatus of the present invention in an initial state before use;

FIG. 3-1 is a perspective view of a half tunnel type door in the experimental apparatus of the present invention;

FIG. 3-2 is a top view of a half tunnel type door in the experimental setup of the present invention;

FIG. 4-1 is a perspective view of a drawing groove of the experimental apparatus of the present invention;

FIG. 4-2 is a schematic cross-sectional view of a drawing groove in the experimental apparatus of the present invention;

FIG. 5 is a flowchart of an experimental method for measuring soft and hard composite formation face stability according to the present invention;

FIG. 6 is a state diagram of the operation process of the simulated primary support structure of the experimental device of the present invention, wherein the soft and hard soil layer samples which are not within the protection scope of the present invention are omitted;

fig. 7 is a state diagram of the using process of the simulated primary support and secondary lining structure of the experimental device of the invention, and the soft and hard soil layer samples which are not in the protection range of the invention are omitted.

Reference numerals:

the model comprises a model frame body 1, a transparent observation plate 2, a half-tunnel-shaped door 3 and a drawing groove 4.

Detailed Description

In order to make the technical solutions of the present application better understood by those skilled in the art, the present invention will be further described in detail by way of examples in conjunction with the accompanying drawings of the specification.

The terms of orientation such as up, down, left, right, front, and rear in the present specification are established based on the positional relationship shown in the drawings. The corresponding positional relationship may also vary depending on the drawings, and therefore, should not be construed as limiting the scope of protection.

In the present invention, the terms "mounted," "connected," "fixed," and the like are to be understood in a broad sense, and for example, may be fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected or capable of communicating with each other, directly connected, indirectly connected through an intermediate medium, or communicated between two components, or interacting between two components. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.