CN213805251U

CN213805251U - Ultra-high performance concrete-common concrete composite gravity dam

Info

Publication number: CN213805251U
Application number: CN202022767279.XU
Authority: CN
Inventors: 罗军; 苑昕宇; 闫晗菲; 梁岩; 赵军; 张卓航; 赵付林
Original assignee: Zhengzhou University
Current assignee: Zhengzhou University
Priority date: 2020-11-26
Filing date: 2020-11-26
Publication date: 2021-07-27
Anticipated expiration: 2030-11-26

Abstract

The utility model belongs to the technical field of the building, relate to the civil engineering technique in the aspect of the water conservancy, specifically be a compound gravity dam of ultra high performance concrete-ordinary concrete. In order to solve the damage of tensile stress, compressive stress to the dam body during manger plate and earthquake, the utility model discloses a technical scheme be, a compound gravity dam of ultra high performance concrete-ordinary concrete, including dam body and basic dam, the dam body on be provided with dam heel, dam head and roll over slope department, dam heel and dam head roll over slope department and all be provided with first recess, be provided with the enhancement layer in the first recess. The protective layer doped with steel fiber ultra-high performance concrete (UHPC) is arranged on the surface of the dam body, so that the impermeability, the anti-seismic bearing capacity and the durability of the concrete gravity dam are obviously improved.

Description

Ultra-high performance concrete-common concrete composite gravity dam

Technical Field

The utility model belongs to the technical field of the building, relate to the civil engineering technique in the aspect of the water conservancy, specifically be a compound gravity dam of ultra high performance concrete-ordinary concrete.

Background

In recent years, the construction of water conservancy infrastructure in China is developed rapidly. Among them, the reservoir dam plays an important role in national economic development, and has a great impact on agricultural development, industrial construction and production and life of common people. As an old dam with wide application, the gravity dam is mainly maintained to be stable by means of the anti-slip force generated by the dead weight of a dam body. Before the 19 th century, gravity dams were basically built with grouted rubble; in the 20 th century, modern concrete gravity dams are gradually formed. The gravity dam has simple structure, convenient construction, strong flood resistance and strong capacity of resisting accidents such as war damage and the like, and is still widely adopted so far.

Because the concrete gravity dam is large in volume and large in cement consumption, hydration heat and hardening shrinkage of concrete in a construction period can generate unfavorable temperature stress and shrinkage stress, and strict temperature control heat dissipation measures are generally adopted. Many projects develop cracks due to improper temperature control, and some even form harmful cracks, thereby weakening the overall performance of the dam. And the dam body concrete is exposed in water flow and various aggressive media for a long time and can be gradually corroded and damaged, the peripheral concrete is cracked and even peeled off, the water flow leakage problem is caused, and finally the dam body is damaged and destroyed.

In concrete gravity dams, high stress is often generated only in local areas, and the stress is not high in most areas. When water is normally retained, large tensile stress is easily generated at the dam heel and the dam toe, and large tensile stress may occur at the slope breaking position of the dam head when an earthquake occurs. Under a large load, a local area of the dam body is likely to exceed the allowable stress and crack or crush.

SUMMERY OF THE UTILITY MODEL

In order to solve the damage of tensile stress and compressive stress to the dam body during water retaining and earthquake, the utility model discloses a compound gravity dam of ultra high performance concrete-ordinary concrete is through setting up the protective layer that adds steel fibre Ultra High Performance Concrete (UHPC) on the dam body surface, is showing the impermeability, the antidetonation bearing capacity and the durability that improve concrete gravity dam.

The utility model discloses a technical scheme be, a compound gravity dam of ultra high performance concrete-ordinary concrete, including dam body and basic dam, the dam body on be provided with dam heel, dam head and roll over slope department, dam heel and dam head roll over slope department and all be provided with first recess, be provided with the enhancement layer in the first recess.

The dam body on still be provided with the highest water level of upstream side and dam body contact surface, the highest water level of downstream side and dam body contact surface, the highest water level of upstream side and dam body contact surface and the highest water level of downstream side and dam body contact surface all be provided with the second recess, be provided with the protective layer in the second recess.

And a reinforcing mesh is arranged in the reinforcing layer.

The protective layer is internally provided with shear steel bars.

The thickness of the reinforcing layer is 1.5-2.5 m.

The thickness of the protective layer is 30-70 mm.

The utility model has the advantages that:

the reinforced layer and the protective layer are both made of ultra-high performance concrete (UHPC) doped with steel fibers, the gravity dam is a concrete gravity dam, the base material is cement, the compatibility between the two materials is good, and the respective advantages can be fully exerted when the two materials work together.

The traditional concrete gravity dam is easy to face the problem of water leakage during service, influences the exertion of engineering benefits and even shortens the service life of the engineering. The ultra-high performance concrete has a compact structure and extremely small porosity, and is specifically characterized in that durability indexes such as chloride ion permeation resistance and sulfate corrosion resistance are improved by multiple times or even orders of magnitude compared with the traditional concrete in a crack-free state, and the water absorption porosity is only about 1/13 of the traditional concrete. And the addition of the steel fiber can inhibit and restrict the formation and development of UHPC microcracks and obviously improve the cracking resistance of the UHPC. The UHPC is used on the contact surface of the dam body and upstream and downstream water flows, so that the ultrahigh durability of the UHPC can be fully exerted, and the service life of the dam is greatly prolonged.

The compressive strength of the ultra-high performance concrete is higher than 150MPa, which is about 3 times of that of the traditional concrete. When the dam toe is used at the position of the dam toe (the contact surface of the downstream highest water level and the dam body) which is easy to generate large pressure stress, the pressure resistance of the dam toe can be obviously improved.

When water is retained normally, large tensile stress is easily generated at the dam heel; under the action of earthquake, the slope fold of the dam head may have larger tensile stress. The UHPC is used at the two positions and is provided with the reinforcing steel bars, so that the tensile property of the dam heel and the slope fold position of the dam head can be greatly improved, the damage degree of the dam body at the position can be reduced, the dam body can be prevented from generating penetrating cracks, and the seismic resistance of the dam can be obviously improved.

The present invention will be described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the drawing, 1 is a dam body, 2 is an upstream side highest water level and dam body contact surface, 3 is a dam heel, 4 is a dam head slope-folding part, 5 is a downstream side highest water level and dam body contact surface, 6 is shear-resistant steel bars, 7 is a steel bar mesh, 8 is a base dam, 9 is an upstream highest water level, and 10 is a downstream highest water level.

Detailed Description

The ultra-high performance concrete-common concrete composite gravity dam comprises a dam body 1 and a foundation dam 8, wherein a dam heel 3 and a dam head slope folding part 4 are arranged on the dam body 1, first grooves are formed in the dam heel 3 and the dam head slope folding part 4, and reinforcing layers are arranged in the first grooves. The reinforcing mesh 7 is arranged in the reinforcing layer, and the thickness of the reinforcing layer is 1.5-2.5 m.

The upstream maximum water level 9 and the downstream maximum water level 10 are the water flow reference levels. The dam body 1 is further provided with an upstream side highest water level and dam body contact surface 2 and a downstream side highest water level and dam body contact surface 5, the upstream side highest water level and dam body contact surface 2 and the downstream side highest water level and dam body contact surface 5 are both provided with second grooves, and protective layers are arranged in the second grooves. The protective layer is internally provided with shear steel bars 6, and the thickness of the protective layer is 30-70 mm.

The utility model discloses when concrete construction:

the method comprises the following steps: densely distributing a reinforcing mesh 7 at the dam heel 3, vertically arranging a side die, pouring UHPC inwards, pouring the height of about 2m (the specific size is based on the actual engineering), and performing high-temperature steam curing. The curing conditions are required to meet the requirements, and the specific curing conditions are that the curing time is not less than 72 hours when the curing temperature is constant at 80-90 ℃; when the curing temperature is constant at 90-100 ℃, the curing time is not less than 48 h; the relative humidity in the curing environment is not lower than 95%.

Step two: and after the position of the dam heel 3 is built, a gravity dam body 1 is built according to a conventional method, and concrete is poured.

Step three: a first groove with the thickness of about 2m is reserved at a dam head slope fold 4, second grooves with the thickness of about 50mm are reserved at a water flow upstream side highest water level and dam body contact surface 2 and a water flow downstream side highest water level and dam body contact surface 5, a plurality of shear steel bars are implanted into concrete in the two grooves along the height direction and the width direction of the dam body 1, the length of the part of the shear steel bars extending out of the surface of the concrete dam body 1 is about 20mm, and the horizontal distance and the longitudinal distance of adjacent shear steel bars are about 50-250mm (the specific size is based on actual engineering).

The dam head slope fold 4 adopts the same method for constructing the dam heel 3, namely densely distributing the reinforcing mesh 7, pouring UHPC and carrying out high-temperature steam curing.

And the reserved second grooves of the contact surface 2 of the highest water level on the upstream side of the water flow and the dam body and the contact surface 5 of the highest water level on the downstream side of the water flow and the dam body are roughened. The UHPC is evenly coated on the surface of the concrete dam body 1 implanted with the shear steel bars 6, and the UHPC is required to completely coat the part of the shear steel bars 6 extending out of the surface of the concrete dam body 1. And (5) after finishing the coating, performing high-temperature steam curing.

Step four: and then the construction of the rest part of the dam body 1 is continuously completed. And ending the whole construction process.

Claims

1. An ultra-high-performance concrete-ordinary concrete composite gravity dam, comprising a dam body (1) and a foundation dam (8), and the dam body (1) is provided with a dam heel (3) and a dam head folded slope (4), characterized in that: the dam heel (3) and the dam head folded slope (4) are provided with a first groove, and a reinforcement layer is provided in the first groove.

2. An ultra-high performance concrete-ordinary concrete composite gravity dam according to claim 1, characterized in that: the dam body (1) is further provided with a contact surface (2) between the highest water level on the upstream side and the dam body , the contact surface (5) between the highest water level on the downstream side and the dam body, the contact surface (2) between the highest water level on the upstream side and the dam body and the contact surface (5) between the highest water level on the downstream side and the dam body are all provided with a second groove, A protective layer is arranged in the second groove.

3 . The ultra-high performance concrete-common concrete composite gravity dam according to claim 1 , wherein the reinforcing layer has a built-in steel mesh ( 7 ). 4 .

4 . The ultra-high performance concrete-compound concrete gravity dam according to claim 2 , wherein the protective layer has built-in shearing steel bars ( 6 ). 5 .

5 . The ultra-high performance concrete-compound concrete gravity dam according to claim 1 , wherein the thickness of the reinforcing layer is 1.5-2.5 m. 6 .

6 . The ultra-high performance concrete-common concrete composite gravity dam according to claim 2 , wherein the thickness of the protective layer is 30-70 mm. 7 .