CN110532675B - Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern - Google Patents
Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern Download PDFInfo
- Publication number
- CN110532675B CN110532675B CN201910796193.9A CN201910796193A CN110532675B CN 110532675 B CN110532675 B CN 110532675B CN 201910796193 A CN201910796193 A CN 201910796193A CN 110532675 B CN110532675 B CN 110532675B
- Authority
- CN
- China
- Prior art keywords
- span
- arch
- collapse
- ultra
- determining
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
Landscapes
- Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
- Lining And Supports For Tunnels (AREA)
Abstract
The invention relates to an optimal design method suitable for determining the top arch sagittal ratio of an ultra-large span underground cavern. The technical scheme of the invention is as follows: according to the span required by engineering, two parallel test support holes are excavated, and the distance between the axes of the two test support holes is the span required by engineering; performing expanding excavation on the two test branch holes, and excavating from one test branch hole to the other test branch hole until a large-span flat strip-shaped underground space is formed by excavation; placing the large-span flat strip-shaped underground space to enable the roof arch to naturally collapse until the collapse is stable, wherein the condition for judging the collapse is that the collapse does not continue to develop within 1 month; obtaining the roof arch form of the underground space after collapse is stable; the average height h of the top arch mid-1/3 area is determined. The invention is suitable for the fields of traffic, water conservancy and hydropower, national defense and military, and the like.
Description
Technical Field
The invention relates to an optimal design method suitable for determining the top arch sagittal ratio of an ultra-large span underground cavern. Is suitable for the fields of traffic, water conservancy and hydropower, national defense and military, and the like.
Background
The design of the cross section form of the ultra-large-scale underground cavern is lack of mature theoretical methods and effective technical means. The largest international permanent civil underground space is the norway rink, span 61m, sagittal ratio 0.2. The engineering is built in granite with excellent rock mass quality and has extremely low ground stress, so that the sagittal ratio design experience of the engineering cannot be popularized to the condition of common rock mass quality or middle-high ground stress.
At present, the maximum-scale gallery type underground plant in the domestic hydropower industry has a span of 34m, other gallery type underground spaces generally span 16-30 m, and because the hydropower plant has a high excavation height, the value interval of the sagittal ratio range of the designed underground plant is 0.22-0.33 through statistics of design parameters of more than 100 established underground plants, and the design experience mainly comes from medium-low stress conditions, has a smaller span and cannot be directly popularized to the ultra-large span condition of 60-90 m.
Disclosure of Invention
The invention aims to solve the technical problems that: aiming at the problems, the optimal design method suitable for determining the top arch and sagittal span ratio of the ultra-large-span underground cavern is provided.
The technical scheme adopted by the invention is as follows: an optimal design method suitable for determining the top arch sagittal ratio of an ultra-large span underground cavern, wherein the ultra-large span is 60-90 m in length, and is characterized in that:
according to the span required by the engineering, two test support holes which are arranged in parallel are excavated, and the interval between the axes of the two test support holes is the span required by the engineering;
performing expanding excavation on the two test branch holes, and excavating from one test branch hole to the other test branch hole until a large-span flat strip-shaped underground space is formed by excavation;
placing the large-span flat strip-shaped underground space to enable the roof arch to naturally collapse until the collapse is stable, wherein the condition for judging the collapse is that the collapse does not continue to develop within 1 month;
obtaining the roof arch form of the underground space after collapse is stable;
determining the average height h of a 1/3 area in the middle of the top arch;
determining A, B, C three points on the same cross section of the underground space, wherein the point A is positioned at the center of the underground space and the height is 1.1h, and the point B and the point C are respectively positioned at the two side edges of the top arch of the underground space;
fitting A, B, C three points to form an arc, and taking the arc as a natural roof arch for fitting;
and 5% -10% of the sagittal ratio of the fitted natural roof arch is added to be used as the optimal sagittal ratio of the design under the geological condition of the test branch hole.
And if the method is applied to the design of other span vector ratios under the same geological condition, adopting a LargeCave constitutive model to fit the natural slump arch form, obtaining the residual elastic modulus, the residual cohesive force, the residual friction angle and the residual expansion angle, and calculating the natural slump arch of other spans according to the parameters.
The test support hole is rectangular or gate-shaped in excavation outline, and the height is 5-8 m.
The length of the test support hole is more than or equal to 2 times of the design span.
The single expanding and excavating length of the test branch hole in the width direction is less than or equal to 3m, and the excavating length in the axial direction is less than or equal to 4m.
And when the rock columns between the two experimental branch holes are to be expanded and dug to be smaller than 10m, adopting presplitting blasting, blasting and digging the rock columns at one time, and arranging slag discharge.
And measuring and acquiring the roof arch form of the underground space after the collapse is stabilized by adopting laser scanning equipment.
And after the test support hole is excavated, only the top arch of the test support hole is subjected to shotcrete support, and the block is reinforced by the random anchor rods.
The beneficial effects of the invention are as follows: the invention is based on field test and combines calculation and analysis to obtain the optimal natural stable sagittal ratio as the important input parameter of design. According to the invention, through a design innovation field test, the natural stable sagittal ratio of the 60-90 m span underground space is determined, and through numerical analysis based on the LargeCave constitutive model, the natural slump stable sagittal ratio after span, height, ground stress and rock mass quality are changed is determined, and finally the optimal sagittal ratio of the ultra-large span cavity is determined.
Drawings
FIG. 1 is a schematic plan view of two test holes according to an embodiment.
FIG. 2 is a schematic cross-sectional view of two test cavities according to an embodiment.
Fig. 3 and 4 are schematic diagrams of two test holes in the embodiment.
FIG. 5 is a schematic diagram showing the expansion and digging of two test holes until collapse occurs in the embodiment.
FIG. 6 is a schematic illustration of two test holes penetrating in an embodiment.
Fig. 7 is a schematic view of a natural crown fitted in an embodiment.
1. Testing the branch hole; 2. expanding and digging a branch hole; 3. large span flat strip underground space.
Detailed Description
The embodiment is an optimal design method suitable for determining the top arch sagittal ratio of an ultra-large span underground cavity, and comprises the following specific steps:
according to the required span of engineering, two parallel arrangement's experimental hole of branch are excavated, ensure that two hole axis interval is the required span of engineering design, and experimental hole adopts rectangle or the arrangement of city door opening shape, and height 5~8m to the construction is convenient to confirm experimental hole size as the principle (see fig. 1, fig. 2). The length of the test branch hole is not suitable to be less than 2 times of the design span.
After the two parallel arranged test support holes are excavated, the shotcrete support is only carried out on the top arch, and the blocks are reinforced by random anchor rods, so that the subsequent construction safety is ensured. GSI scores along the test hole are recorded, joint information along the test hole is counted, and basic data of rock mass intensity calculation of the engineering area are obtained.
Gradually excavating a rock column between two test branch holes, expanding and excavating the two test branch holes, excavating from one test branch hole to the other test branch hole, and symmetrically constructing (see figures 3 and 4) to form the expanded and excavated branch hole. The single expanding excavation in the width direction is not more than 3m; the excavation footage in the axial direction is based on the principles of safe construction and convenient construction, and the excavation footage in the axial direction is not more than 4m.
The roof arch is excavated by expansion until natural collapse occurs, as shown in fig. 5, and the roof arch is supported by spraying concrete to ensure construction safety. And (3) continuing to dig until the two test branch holes are completely communicated in the width direction, releasing the collapse of the roof arch to develop, and only removing the slag after collapse until the collapse is stable, wherein the collapse is not continuously developed within 1 month when the collapse stability condition is judged, as shown in fig. 6.
The magnitude of the maximum self-stabilizing span is different under different geological and ground stress conditions. The expansion and digging to the top arch can not be self-stabilized, and the construction safety is particularly required to be paid attention to. And when the rock column between the two test branch holes is smaller than 10m, pre-splitting blasting can be adopted to perform blasting and excavation on the rock column at one time, and slag discharge is arranged.
And measuring the natural stable arch form of the cavity along the line by adopting laser scanning equipment.
Dividing the underground space after slump stabilization into three parts in the width direction, and determining the average height h of a 1/3 area in the middle of the natural slump stabilization arch.
Three points A, B, C are determined on the same cross section of the underground space, wherein the point A is positioned at the center of the underground space and the height is 1.1h, and the point B and the point C are respectively positioned at two side edges of the top arch of the underground space (see figure 7).
The three points of the fitting A, B, C form an arc, which serves as a natural roof of the fitting.
The fitted natural roof arch is not the optimal design sagittal ratio, and the value still needs to be increased by 5% -10% to be used as the optimal design sagittal ratio under the geological condition of the test branch hole.
If the design data need to be applied to the design of other span vector ratios under the same geological condition, the LargeCave constitutive model can be adopted to fit the natural slump arch form, so as to obtain the residual elastic modulus, the residual cohesive force, the residual friction angle and the residual expansion angle, and the natural slump arch of other spans can be calculated according to the parameters.
Claims (7)
1. An optimal design method suitable for determining the top arch sagittal ratio of an ultra-large span underground cavern, wherein the ultra-large span is 60-90 m in span, and is characterized in that:
according to the span required by the engineering, two test support holes which are arranged in parallel are excavated, and the interval between the axes of the two test support holes is the span required by the engineering;
performing expanding excavation on the two test branch holes, and excavating from one test branch hole to the other test branch hole until a large-span flat strip-shaped underground space is formed by excavation;
placing the large-span flat strip-shaped underground space to enable the roof arch to naturally collapse until the collapse is stable, wherein the condition for judging the collapse is that the collapse does not continue to develop within 1 month;
obtaining the roof arch form of the underground space after collapse is stable;
determining the average height h of a 1/3 area in the middle of the top arch;
determining A, B, C three points on the same cross section of the underground space, wherein the point A is positioned at the center of the underground space and the height is 1.1h, and the point B and the point C are respectively positioned at the two side edges of the top arch of the underground space;
fitting A, B, C three points to form an arc, and taking the arc as a natural roof arch for fitting;
and 5% -10% of the sagittal ratio of the fitted natural roof arch is added to be used as the optimal sagittal ratio of the design under the geological condition of the test branch hole.
2. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1, wherein the method comprises the following steps: and if the method is applied to the design of other span vector ratios under the same geological condition, adopting a LargeCave constitutive model to fit the natural slump arch form, obtaining the residual elastic modulus, the residual cohesive force, the residual friction angle and the residual expansion angle, and calculating the natural slump arch of other spans according to the parameters.
3. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1 or 2, wherein the method comprises the following steps: the test support hole is rectangular or gate-shaped in excavation outline, and the height is 5-8 m.
4. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1 or 2, wherein the method comprises the following steps: the single expanding and excavating length of the test branch hole in the width direction is less than or equal to 3m, and the excavating length in the axial direction is less than or equal to 4m.
5. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1 or 2, wherein the method comprises the following steps: and when the rock columns between the two experimental branch holes are to be expanded and dug to be smaller than 10m, adopting presplitting blasting, blasting and digging the rock columns at one time, and arranging slag discharge.
6. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1 or 2, wherein the method comprises the following steps: and measuring and acquiring the roof arch form of the underground space after the collapse is stabilized by adopting laser scanning equipment.
7. The optimal design method for determining the top arch sagittal ratio of the ultra-large span underground cavern according to claim 1 or 2, wherein the method comprises the following steps: and after the test support hole is excavated, only the top arch of the test support hole is subjected to shotcrete support, and the block is reinforced by the random anchor rods.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910796193.9A CN110532675B (en) | 2019-08-27 | 2019-08-27 | Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910796193.9A CN110532675B (en) | 2019-08-27 | 2019-08-27 | Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110532675A CN110532675A (en) | 2019-12-03 |
| CN110532675B true CN110532675B (en) | 2023-08-22 |
Family
ID=68664435
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910796193.9A Active CN110532675B (en) | 2019-08-27 | 2019-08-27 | Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110532675B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101864959A (en) * | 2009-04-17 | 2010-10-20 | 中铁工程设计咨询集团有限公司 | Method for tunneling construction of main structure of underground station |
| CN103321653A (en) * | 2013-06-27 | 2013-09-25 | 中国水电顾问集团成都勘测设计研究院 | Method of treating lining after collapse of underground cavern crown |
| US20180003054A1 (en) * | 2014-06-13 | 2018-01-04 | Changjiang Survey Planning Design And Research Co. Ltd. | Construction layout for underground caverns in nuclear island powerhouse of underground nuclear power plant |
| US20180003056A1 (en) * | 2014-06-13 | 2018-01-04 | Changjiang Survey Planning Design And Research Co., Ltd. | Construction layout for caverns of underground nuclear power plant |
-
2019
- 2019-08-27 CN CN201910796193.9A patent/CN110532675B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101864959A (en) * | 2009-04-17 | 2010-10-20 | 中铁工程设计咨询集团有限公司 | Method for tunneling construction of main structure of underground station |
| CN103321653A (en) * | 2013-06-27 | 2013-09-25 | 中国水电顾问集团成都勘测设计研究院 | Method of treating lining after collapse of underground cavern crown |
| US20180003054A1 (en) * | 2014-06-13 | 2018-01-04 | Changjiang Survey Planning Design And Research Co. Ltd. | Construction layout for underground caverns in nuclear island powerhouse of underground nuclear power plant |
| US20180003056A1 (en) * | 2014-06-13 | 2018-01-04 | Changjiang Survey Planning Design And Research Co., Ltd. | Construction layout for caverns of underground nuclear power plant |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110532675A (en) | 2019-12-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105839643B (en) | A kind of tunnel construction method of use pattern foundation pit supporting structure | |
| CN101144384B (en) | Tunnel engineering non-blasting weak disturbance excavating method | |
| CN109736827B (en) | Method for excavating urban subway hard rock stratum communication channel by high-pressure gas expansion fracturing | |
| CN105952460A (en) | Non-blasting construction method of hard-rock tunnel in city | |
| Kovári | History of the sprayed concrete lining method—part II: milestones up to the 1960s | |
| CN103899318A (en) | Medium ground tunnel milling excavating and mating mechanized construction method | |
| CN109918851B (en) | On-site rapid estimation method for scale of deep tunnel rockburst disaster | |
| CN110344861A (en) | The quick construction method of lithostratigraphy super-span underground engineering and its structure | |
| CN110629671A (en) | Suspension bridge anchorage and construction method thereof | |
| CN203925513U (en) | The tunnel portal liner structure in steep location, slope is faced upward on limit | |
| CN110532675B (en) | Optimal design method suitable for determining top arch sagittal ratio of ultra-large span underground cavern | |
| CN104930937A (en) | Circular divided blasting tunnel construction method capable of effectively controlling blasting vibration velocity | |
| CN110030001B (en) | Construction method for mountain tunnel to go out of hole | |
| KR20020028404A (en) | Excavation and support construction by underground space and TUNNEL small section split ADVANCE blasting | |
| CN211395370U (en) | Suspension bridge anchorage | |
| CN104792236B (en) | A kind of method of rock slope V-type groove explosive forming | |
| CN106012972A (en) | High dam bank slope safety protection facility layout construction method | |
| CN103437780A (en) | Coal mine tunnel timbering method for recovering working resistance from fatigue resistance state | |
| CN212250062U (en) | Supporting construction of underground cavern | |
| CN211621611U (en) | Deep foundation pit steel box girder supporting structure | |
| Leichnitz | Analysis of collapses on tunnel construction sites on the new lines of the German Federal Railway | |
| CN102277851B (en) | Concrete gravity dam construction teaching model and construction method thereof | |
| CN113898371B (en) | Synchronous construction method for tunnel anchors and bifurcation tunnel proximity engineering distributed up and down in space | |
| CN207254469U (en) | A kind of simple cubic meter of stone abolishes instrument | |
| CN220789773U (en) | Earth and stone square support device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |