CN115899391A - A steel-lined-steel-concrete prefabricated composite structure pressure pipe and its construction method - Google Patents

Abstract

The invention provides a steel lining-section steel concrete prefabricated combined structure pressure pipe which comprises backfilling concrete and a prefabricated combined structure, wherein the backfilling concrete is positioned between a surrounding rock excavation boundary line and the prefabricated combined structure, and the prefabricated combined structure comprises a steel lining, section steel and lining concrete; the lining concrete is arranged between the backfilled concrete and the steel lining, the section steel is positioned in the lining concrete, and the section steel is connected with the steel lining; the circumferential joint of the steel lining adopts inner side single-side groove welding; the steel lining-steel reinforced concrete prefabricated combined structure has the advantages that the contribution of the section steel is considered in the overall strength, the total thickness of the steel lining can be effectively reduced, the unit manufacturing cost of the pressure pipe is reduced, the thickness of the steel lining is reduced, the circumferential welding line is welded by adopting an inner side single-sided groove, the welding from the outer side is avoided, and the problem of difficult welding from the outer side is solved; the section steel can be used as a stiffening rib, so that the stability requirement of the structure under the external pressure can be ensured; the thickness of the steel lining is reduced, the weight is reduced, the length of a single section of the steel lining can be increased, and the number of circumferential seams is reduced.

Description

A steel-lined-steel-concrete prefabricated composite structure pressure pipe and its construction method

technical field

The invention belongs to the field of pressure pipe structures, and relates to a steel lining-steel concrete prefabricated composite structure pressure pipe and a construction method thereof.

Background technique

At present, the investment in pumped storage power stations is relatively large, and the unit cost per kilowatt is about 6,000 yuan, of which the hub project accounts for about 60%. The high-pressure steel pipe is a common structure for the water delivery system of a high-head power station. Its structural form is mainly a single steel lining with backfilled concrete on the outside. In order to ensure the stability of the steel lining under external water pressure, it is necessary to add circumferential stiffeners to the outside of the steel lining. Stiffeners account for about 15% of the total high-pressure steel pipes. The thickness of the steel lining required by the single steel lining structure is relatively large, and double-sided groove welding is often used for the circumferential seam of the steel lining, while the outer weld seam is not only slow in construction but also difficult to guarantee the construction quality due to the narrow construction space on site. The unit cost of penstock steel lining is as high as 15,000-30,000 yuan/ton, which is 2-4 times the unit cost of ordinary steel. Therefore, it is necessary to improve the structural form of high-pressure water delivery steel pipes in terms of construction period and cost, so that steel linings with low strength and thin thickness should be used as much as possible in the low water head section.

Contents of the invention

The object of the present invention is to solve the above-mentioned problems in the prior art, and provide a steel-lined-steel-concrete prefabricated composite structure pressure pipe. Welding; the structure only needs to consider the construction error, which can reduce the thickness of backfill concrete on the outside; the section steel can also be used as a stiffener to ensure the stability of the structure under external pressure; the steel lining is connected by single-sided groove welding on the inside; the prefabricated structure is adopted The construction cycle design is saved, the thinking is clear, and it is easy to implement.

In order to achieve the above object, the solution adopted by the present invention is: a steel liner-steel concrete prefabricated composite structure pressure pipe, including backfilled concrete and prefabricated composite structure, the backfilled concrete is located between the surrounding rock excavation boundary line and the prefabricated composite structure, and the prefabricated Composite structure includes steel lining, section steel and lining concrete;

The lining concrete is set between the backfill concrete and the steel lining, the section steel is located in the lining concrete, and the section steel is connected to the steel lining; the circular joint of the steel lining adopts inner single-sided groove welding.

Backfill concrete and lining concrete adopt micro-expansion concrete, fiber concrete or micro-expansion fiber concrete.

Multiple strips of section steel are arranged horizontally around the steel lining.

The section steel adopts T-section steel or angle steel.

The section steel and the steel lining are welded.

The prefabricated combined structure is prefabricated in the factory as a whole.

The construction method of the steel lining-steel concrete prefabricated composite structure pressure pipe of the present invention is characterized in that it comprises the following steps:

1) After the excavation of the water pipe cavern is completed, the grouting pipe is reserved on the rock wall;

2) Construction consolidation slurry pipe;

3) Install the prefabricated composite structure and construct the steel lining circumferential seam of the prefabricated composite structure;

4) Construction backfill concrete;

5) Construction backfill grouting and contact grouting;

The construction step 4) and the construction step 3) are interleaved.

Compared with the prior art, the present invention has the following beneficial effects:

The steel lining-section steel concrete prefabricated composite structure takes into account the contribution of section steel. Section steel can also be used as stiffeners to ensure the stability of the structure under external pressure. It can effectively reduce the total thickness of steel lining and reduce the unit cost of pressure pipes. The thickness of the steel lining is reduced, so that it can be welded on one side only on the inner side, avoiding welding from the outer side, and solving the problem of difficult welding on the outer side; the thickness of backfill concrete can only consider the construction error; the thickness of the steel lining is reduced The weight is reduced, the length of single-section steel lining can be increased, and the number of circumferential joints can be reduced. The design flow of the invention is clear, which not only saves engineering quantity and construction period, but also is easy to implement on site.

Furthermore, the whole prefabricated composite structure is prefabricated in a factory, which saves the construction period and improves the quality of the prefabricated composite structure.

Description of drawings

Fig. 1 is a cross-sectional schematic diagram of the present invention;

Fig. 2 is the schematic diagram of the cross-sectional structure of the prefabricated composite structure of the present invention;

Fig. 3 is a three-dimensional view of the prefabricated combined structure of the present invention;

Fig. 4 is the schematic diagram of single-sided groove welding of steel lining ring in the present invention;

In the attached drawings: 1-surrounding rock excavation boundary line; 2-backfill concrete; 3-steel lining; 32-shaped steel; 33-lining concrete.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the pressure pipe of the steel liner-shaped steel concrete prefabricated composite structure of the present invention has surrounding rock on the outside, including backfill concrete 2 and prefabricated composite structure 3, and the prefabricated composite structure 3 includes steel lining 31. Section steel 32 and lining concrete 33; the backfill concrete 2 is located between the surrounding rock excavation boundary line 1 and the prefabricated composite structure 3, the lining concrete 33 is located between the backfill concrete 2 and the steel lining 31, and the section steel 32 is located inside the lining concrete 33, The section steel 32 is connected with the steel lining 31, and the circumferential seam of the steel lining 31 adopts inner single-sided groove welding.

The section steel 32 is connected with the steel lining 31, and the section steel itself has rigidity. After connecting with the steel lining 31 and combining the backfilling concrete 2, the resistance of the steel lining 31 can be increased, and the rigidity of the prefabricated composite structure 3 can also be improved, so that it can be applied to rigidity There are more demanding working conditions.

Among them, the backfill concrete 2 and the lining concrete 33 adopt micro-expansion concrete, fiber concrete or micro-expansion fiber concrete, and the specific micro-expansion concrete, fiber concrete or micro-expansion fiber concrete and their thickness are adopted according to different requirements of actual projects.

Optionally, a plurality of section steels 32 are arranged horizontally around the steel lining 31 using T-shaped steel or angle steel, and the section steel 32 and the steel lining 31 are welded.

The steel lining 31 is made of ordinary steel or high-strength steel, and the section steel 32 is made of Q235 or Q355.

The steel liner-shaped steel concrete prefabricated composite structure pressure pipe of the present invention comprises the following steps:

1) After the excavation of the water pipe cavern is completed, the grouting pipe is reserved on the rock wall;

2) Consolidate the grout pipe; construct the consolidated grout pipe according to existing conventional construction methods;

3) Install the prefabricated composite structure 3, construct the prefabricated composite structure 3, weld the steel lining 31 circumferential seams;

4) construction backfill concrete 2;

5) Construction backfill grouting and contact grouting;

Wherein, the construction step 4) and the construction step 3) can be carried out alternately.

The present invention is characterized in the following aspects:

In summary, the overall strength of the steel lining-steel concrete prefabricated composite structure takes into account the contribution of the steel 32, which can effectively reduce the total thickness of the steel lining and reduce the unit cost of the pressure pipe. Single-sided groove welding avoids welding from the outside and solves the problem of difficulty in welding from the outside. The thickness of backfill concrete 1 can only consider the construction error. Section steel 32 can also be used as a stiffener to ensure the stability of the structure under external pressure. The thickness of the steel lining 32 is reduced and the quality is reduced, which can increase the length of a single steel lining and reduce the number of circumferential seams. The prefabricated composite structure 3 adopts prefabricated components, which saves the construction period. The invention not only saves engineering quantity and construction period, but also is easy to implement on site.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those of ordinary skill in the art can still modify or equivalently replace the specific embodiments of the present invention without departing from the spirit and principles of the present invention. Modifications or equivalent replacements all fall within the protection scope of the claims of the present invention.

Claims (8)

1. The steel lining-section steel concrete prefabricated combined structure pressure pipe is characterized by comprising backfilling concrete (2) and a prefabricated combined structure (3), wherein the backfilling concrete (2) is positioned between a surrounding rock excavation boundary line (1) and the prefabricated combined structure (3), and the prefabricated combined structure (3) comprises a steel lining (31), section steel (32) and lining concrete (33);

the lining concrete (33) is arranged between the backfilling concrete (2) and the steel lining (31), the section steel (32) is positioned in the lining concrete (33), and the section steel (32) is connected with the steel lining (31); the circumferential joint of the steel lining (31) adopts inner side single-side groove welding.

2. The steel lining-steel reinforced concrete prefabricated combined structure pressure pipe according to claim 1, wherein the backfill concrete (2) and the lining concrete (33) adopt micro-expansion concrete, fiber concrete or micro-expansion fiber concrete.

3. The steel lining-steel reinforced concrete prefabricated combined structure pressure pipe as claimed in claim 1, wherein: the section steel (32) is provided in a plurality of strips in the horizontal direction around the steel liner (31).

4. The steel lining-steel reinforced concrete prefabricated combined structure pressure pipe as claimed in claim 1, wherein said steel section (32) is a T-shaped steel or an angle steel.

5. The steel lining-steel reinforced concrete prefabricated combined structure pressure pipe as claimed in claim 1, wherein the steel section (32) and the steel lining (31) are welded.

6. The steel lining-steel reinforced concrete prefabricated combined structure pressure pipe according to claim 1, characterized in that the prefabricated combined structure (3) is integrally prefabricated in a factory.

7. The construction method of the steel lining-steel reinforced concrete prefabricated combined structure pressure pipe as claimed in any one of claims 1 to 6, which comprises the steps of:

1) Reserving grouting pipes on the rock wall after the water delivery pipe cavern is excavated;

2) Constructing a consolidation slurry pipe;

3) Installing the prefabricated composite structure (3), and constructing a circumferential seam of a steel lining (31) of the prefabricated composite structure (3);

4) Constructing backfill concrete (2);

5) Construction backfill grouting and contact grouting.

8. Construction method according to claim 7, characterized in that the construction step 4) is carried out crosswise to the construction step 3).

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