Cofferdam riprap slope protection reinforcing structure and construction method

Abstract

The invention discloses a cofferdam riprap slope protection reinforcing structure and a construction method, and relates to the technical field of engineering construction. The cofferdam riprap slope protection reinforcing structure comprises a cofferdam base body, a first cofferdam body and a second cofferdam body. A first anti-seepage isolation structure, a second anti-seepage isolation structure and reinforcing steel bars are arranged at the bottom of the second cofferdam body; a first riprap slope protection structure is arranged at the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is arranged at the upper end of the second anti-seepage isolation structure. The construction method comprises the steps that the steel bars are driven into a soil layer of the ground at intervals at the bottom of the cofferdam base body; a first anti-seepage isolation structure and a second anti-seepage isolation structure are arranged at the ends of the steel bars. A first riprap slope protection structure is arranged at the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is arranged at the upper end of the second anti-seepage isolation structure; a plurality of coarse sand bags are laid on the first side face of the first riprap slope protection structure, and a reinforcing rockfill layer is arranged on the second side face. According to the scheme, the effect that the bottom of the cofferdam protection foot is prevented from being emptied due to the water level is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of engineering construction, and in particular to a cofferdam riprap slope reinforcement structure and a construction method. Background Art

[0002] During the river channel construction, in order to set up construction equipment such as pumps and gates, a water retaining cofferdam must be used to ensure the safety and reliability of dry land operations in the foundation pit during construction. Earth-rock cofferdams are mostly used in existing construction. When earth-rock cofferdams are used, there are mainly the following anti-seepage methods: clay inclined wall on the upstream slope or combined with blanketing for anti-seepage, clay core wall for anti-seepage, and waterproof geomembrane for anti-seepage at the axis of the cofferdam. For clay core wall or waterproof geomembrane anti-seepage cofferdam, its underwater part needs to be treated with concrete anti-seepage wall or high-pressure jet anti-seepage wall. For clay inclined wall anti-seepage, there are problems such as difficulty in implementation in water and poor guarantee of anti-seepage effect; and in the case of dense water networks, earth-rock cofferdams built in tidal areas with more silt in the surrounding areas are prone to settlement and displacement due to geological and water scouring.

[0003] Therefore, in order to ensure that the clay cofferdam footing will not be washed away by floods during the flood season and that the bottom soil layer will not be carried away by the water level change, a protective reinforcement structure and construction method for the riprap footing is proposed. Summary of the invention

[0004] The invention aims at the problems existing in the prior art and provides a cofferdam riprap slope reinforcement structure and a construction method.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A cofferdam riprap slope reinforcement structure comprises a cofferdam base, a first weir body and a second weir body, wherein the first weir body and the second weir body are arranged on the cofferdam base, and the first weir body is arranged on the backwater side of the second weir body; a first anti-seepage isolation structure, a second anti-seepage isolation structure and a plurality of steel bars are arranged at the bottom of the second weir body, and the first anti-seepage isolation structure and the second anti-seepage isolation structure are connected; the first anti-seepage isolation structure and the second anti-seepage isolation structure have the same structure, both of which include a clay layer, a geogrid layer and a mortar layer arranged in sequence from the direction close to the steel bars to the direction away from the steel bars; wherein a plurality of steel bars are inserted under the clay layer; a first riprap slope protection structure is arranged at the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is arranged at the upper end of the second anti-seepage isolation structure.

[0007] Based on the above technical solution, further, the geogrid layer is in contact with the upper end of the steel bar, a clay layer is arranged below the geogrid layer, and a slurry layer is arranged above the geogrid.

[0008] Based on the above technical solution, further, the slurry layer is composed of cement slurry.

[0009] Based on the above technical solution, further, the first anti-seepage isolation structure and the second anti-seepage isolation structure are connected as a whole, and the angle between the connection positions is 120°-150°

[0010] Based on the above technical solution, further, the first riprap slope protection structure and the second riprap slope protection structure have the same structure, both of which are composed of cement and riprap.

[0011] Based on the above technical solution, further, a plurality of coarse sand bags are provided on the first side surface exposed outside the first riprap slope protection structure, wherein the first side surface is perpendicular to the ground.

[0012] Based on the above technical solution, further, a reinforced rockfill layer is provided on the second side surface exposed outside the first riprap slope protection structure, wherein the second side surface is parallel to the ground.

[0013] Based on the above technical solution, further, the total weight of the reinforced rockfill layer is less than the total weight of the first riprap slope protection structure.

[0014] Based on the above technical solution, further, a barrier layer is provided at the end of the second riprap slope protection structure extending upward, and the barrier layer is integrally formed with the second riprap slope protection structure.

[0015] A construction method of a cofferdam riprap slope reinforcement structure is implemented by using a cofferdam riprap slope reinforcement structure, and includes the following construction steps:

[0016] Step 1: At the bottom of the cofferdam base, use plum blossom piles to drive several steel bars into the soil layer at intervals, and reserve a height of 200mm-300mm;

[0017] Step 2: a first anti-seepage isolation structure and a second anti-seepage isolation structure are provided at the reserved end positions of the steel bars;

[0018] Step 3, a first riprap slope protection structure is arranged on the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is arranged on the upper end of the second anti-seepage isolation structure;

[0019] Step 4: Lay a number of coarse sand bags on the first side of the first riprap slope protection structure, and arrange a reinforced rockfill layer on the second side to complete the construction.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention can prevent the bottom of the cofferdam foot from being hollowed out due to the water level by arranging the first anti-seepage isolation structure and the second anti-seepage isolation structure at the bottom of the second dam body. Specifically, the first anti-seepage isolation structure and the second anti-seepage isolation structure are both composed of a clay layer, a geogrid layer and a slurry layer; at the same time, the bottom of the second base (cofferdam foot) is reinforced by a plurality of steel bars to improve the reinforcement effect.

[0022] (2) The present invention arranges a first riprap slope protection structure and a second riprap slope protection structure on the first anti-seepage isolation structure and the second anti-seepage isolation structure respectively. The first riprap slope protection structure and the second riprap slope protection structure are both made of cement and riprap. The bottom of the first riprap slope protection structure and the bottom of the second riprap slope protection structure are in contact with the mortar layer at the corresponding position, thereby stabilizing the riprap at the corresponding position.

[0023] (3) The present invention further provides a coarse sand bag on the first side surface exposed to the outside of the first riprap slope protection structure, and provides a reinforced rockfill layer on the second side surface. The coarse sand bag is provided on the first side surface to reinforce the stability of the bottom of the first riprap slope protection structure and prevent this position from being washed away by water. The size of the rocks in the reinforced rockfill layer provided on the second side surface is smaller than the size of the rocks in the first riprap slope protection structure. On the one hand, when there may be gaps after the riprap and cement are mixed, the rocks can be used to fill the gaps, thereby achieving the effect of anti-seepage isolation.

[0024] (4) In order to prevent the adverse effect on the entire cofferdam base when the water level is too high, that is, when the water level exceeds the height of the first riprap slope and spreads to the height of the second riprap slope, a barrier layer is provided at the end of the second riprap slope away from the first riprap slope and extends upward. The barrier layer is integrally formed with the second riprap slope structure. The purpose of providing the barrier layer is to prevent high water from entering the high position area of ​​the cofferdam base that is easily permeable, thereby further improving the effect of anti-seepage isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the reinforcement structure of the present invention;

[0026] Figure 2 for Figure 1 A magnified view of part A;

[0027] Figure 3 It is a plan view schematic diagram of the combination of the cofferdam base and the second riprap slope protection structure of the present invention;

[0028] Figure 4 It is a schematic plan view of the cofferdam base and the steel bar combination perspective of the present invention;

[0029] Description of the drawings: 1. cofferdam base; 2. first weir body; 3. second weir body; 4. first anti-seepage isolation structure; 5. second anti-seepage isolation structure; 6. first riprap slope protection structure; 7. second riprap slope protection structure; 8. clay layer; 9. geogrid layer; 10. slurry layer; 11. first side; 12. coarse sandbags; 13. second side; 14. reinforced rockfill layer; 15. barrier layer; 16. steel bars. DETAILED DESCRIPTION

[0030] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0031] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation mode of the present invention is described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0032] In the description of the present invention, it is to be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0033] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for the purpose of distinguishing descriptions, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0034] Example 1

[0035] Combination Figure 1-Figure 4As shown, the present embodiment provides a cofferdam riprap slope reinforcement structure, which includes a cofferdam base 1, a first weir 2 and a second weir 3, wherein the first weir 2 and the second weir 3 are arranged on the cofferdam base 1, and the first weir 2 is arranged on the backwater side of the second weir 3, wherein the bottom position of the second weir 3 is provided with a first anti-seepage isolation structure 4, a second anti-seepage isolation structure 5 and a plurality of steel bars 16, the first anti-seepage isolation structure 4 and the second anti-seepage isolation structure 5 have the same structure, and both include a clay layer 8, a geogrid layer 9 and a slurry layer 10 arranged in sequence from the direction close to the steel bars 16 to the direction away from the steel bars 16, that is, the geogrid The geogrid layer 9 is in contact with the upper end of the steel bar 16, a clay layer 8 is arranged below the geogrid layer 9, and a slurry layer 10 is arranged above the geogrid, and the slurry layer 10 can be selected to be composed of cement slurry; the difference is that the first anti-seepage isolation structure 4 is horizontally arranged at the bottom of the first weir body 2, and the second anti-seepage isolation structure 5 is inclined to the side of the second weir body 3, and the first anti-seepage isolation structure 4 is docked with the second anti-seepage isolation structure 5, and the docking position is closely arranged. If an integrated connection method is adopted, water seepage will not occur. At the same time, the angle between the first anti-seepage isolation structure 4 and the second anti-seepage isolation structure 5 is 120°-150°. Several steel bars 16 are arranged at intervals at the bottom of the second weir body 3, and different lengths of several steel bars 16 are selected according to different actual setting positions. In this embodiment, the first anti-seepage isolation structure 4 and the second anti-seepage isolation structure 5 are arranged to prevent the bottom of the cofferdam base 1 from being hollowed out due to the water level.

[0036] In some specific embodiments, a first riprap slope protection structure 6 is provided at the upper end of the first anti-seepage isolation structure 4, and a second riprap slope protection structure 7 is provided at the upper end of the second anti-seepage isolation structure 5. The first riprap slope protection structure 6 and the second riprap slope protection structure 7 have the same structure, both of which are made of cement and riprap. The bottom of the first riprap slope protection structure 6 and the bottom of the second riprap slope protection structure 7 are in contact with the mortar layer 10 at the corresponding position, which can stabilize the riprap at the corresponding position.

[0037] In some specific embodiments, a coarse sand bag 12 is provided on the first side 11 exposed to the outside of the first riprap slope protection structure 6, and a reinforced rockfill layer 14 is provided on the second side 13. It should be noted that the first side 11 is perpendicular to the ground, the second side 13 is located above the ground, and the second side 13 is parallel to the ground. In this embodiment, the coarse sand bag 12 is provided on the first side 11 to reinforce the stability of the bottom of the first riprap slope protection structure 6 to prevent this position from being washed away by water; the size of the rock in the reinforced rockfill layer 14 provided on the second side 13 is smaller than the size of the rock in the first riprap slope protection structure 6. On the one hand, the rock can fill the gaps that may appear after the riprap and cement are mixed, thereby achieving the effect of anti-seepage isolation. At the same time, when the water level exceeds the height of the first side 11 of the first riprap slope protection and overflows to the second side 13, the reinforced rockfill layer 14 further plays a role in stabilization and anti-seepage isolation. It should be further explained that the total weight of the reinforced rockfill layer 14 is less than the total weight of the first riprap slope protection structure 6 , that is, under the premise, there will be no problem of collapse of the structure below the reinforced rockfill layer 14 due to the weight of the reinforced rockfill layer 14 .

[0038] In some embodiments, in order to prevent the adverse effect on the entire cofferdam base 1 when the water level is too high, that is, when the water level exceeds the height of the first riprap slope protection and spreads to the height of the second riprap slope protection, a barrier layer 15 is provided at the end of the second riprap slope protection structure 7 away from the first riprap slope protection structure 6, and the barrier layer 15 is integrally formed with the second riprap slope protection structure 7. The purpose of setting the barrier layer 15 is to prevent high-water-level water from entering the high-position area of ​​the cofferdam base 1 that is easily permeable, further improving the effect of anti-seepage isolation. It should be noted that the barrier layer 15 can be composed of a mixture of cement and different types of stones, and in order to avoid collapse due to the deadweight of the barrier layer 15, the extended area of ​​the barrier layer 15 is set to be smaller, and the second riprap slope protection structure 7 is sufficient to support the weight of the barrier layer 15 and ensure that it does not collapse.

[0039] Example 2

[0040] This embodiment provides a construction method based on the reinforcement structure described in Embodiment 1, comprising the following steps:

[0041] Step 1: At the bottom of the cofferdam base 1, several steel bars 16 are driven into the ground layer at intervals by means of plum blossom piles, and a preferred height of 200mm-300mm is reserved; the height is reserved to facilitate the arrangement of multiple anti-seepage isolation structures around it;

[0042] Step 2: A first anti-seepage isolation structure 4 and a second anti-seepage isolation structure 5 are provided at the end of the reserved steel bar 16. The first anti-seepage isolation structure 4 and the second anti-seepage isolation structure 5 both include a clay layer 8, a geogrid layer 9 and a slurry layer 10 arranged in sequence from the direction close to the steel bar 16 to the direction away from the steel bar 16. The filling and pressing method can be automatic filling and pressing by mechanical equipment or manual filling and pressing. In this embodiment, the laying height of the clay layer 8 is not higher than the reserved height of the steel bar 16.

[0043] Step 3: a first riprap slope protection structure 6 is arranged on the upper end of the first anti-seepage isolation structure 4, and a second riprap slope protection structure 7 is arranged on the upper end of the second anti-seepage isolation structure 5, so as to bond and reinforce the riprap at the bottom of the cofferdam base 1;

[0044] Step 4: laying a number of coarse sand bags 12 on the first side 11 of the first riprap slope protection structure 6, and providing a reinforced rockfill layer 14 on the second side 13, so as to achieve the effect of further reinforcement and anti-seepage isolation.

[0045] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A cofferdam riprap slope reinforcement structure, characterized in that: It comprises a cofferdam base, a first weir body and a second weir body, wherein the first weir body and the second weir body are arranged on the cofferdam base, and the first weir body is arranged on the backwater side of the second weir body; A first anti-seepage isolation structure, a second anti-seepage isolation structure and a plurality of steel bars are provided at the bottom of the second weir body, and the first anti-seepage isolation structure and the second anti-seepage isolation structure are connected; The first anti-seepage isolation structure and the second anti-seepage isolation structure have the same structure, both of which include a clay layer, a geogrid layer and a slurry layer arranged in sequence from the direction close to the steel bars to the direction far from the steel bars; wherein a plurality of steel bars are inserted under the clay layer; A first riprap slope protection structure is provided on the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is provided on the upper end of the second anti-seepage isolation structure.

2. A cofferdam riprap slope reinforcement structure according to claim 1, characterized in that: The geogrid layer is in contact with the upper end of the steel bar, a clay layer is arranged below the geogrid layer, and a slurry layer is arranged above the geogrid.

3. The cofferdam riprap slope reinforcement structure according to claim 1 is characterized by: The slurry layer is composed of cement slurry.

4. The cofferdam riprap slope reinforcement structure according to claim 1 is characterized in that: The first anti-seepage isolation structure and the second anti-seepage isolation structure are connected as one piece, and the angle between the connection positions is 120°-150°.

5. The cofferdam riprap slope reinforcement structure according to claim 1 is characterized by: The first riprap slope protection structure and the second riprap slope protection structure have the same structure, both of which are made of cement and riprap.

6. The cofferdam riprap slope reinforcement structure according to claim 1, characterized in that: A plurality of coarse sand bags are arranged on a first side surface exposed outside the first riprap slope protection structure, wherein the first side surface is perpendicular to the ground.

7. The cofferdam riprap slope reinforcement structure according to claim 1 is characterized by: A reinforced rockfill layer is provided on a second side surface exposed outside the first riprap slope protection structure, wherein the second side surface is parallel to the ground.

8. The cofferdam riprap slope reinforcement structure according to claim 7, characterized in that: The total weight of the reinforced rockfill layer is less than the total weight of the first riprap slope protection structure.

9. The cofferdam riprap slope reinforcement structure according to claim 1, characterized in that: An isolation layer is provided at the end of the second riprap slope protection structure extending upward, and the isolation layer is integrally formed with the second riprap slope protection structure.

10. A construction method for a cofferdam riprap slope reinforcement structure, characterized in that: The invention is realized by using a cofferdam riprap slope reinforcement structure as claimed in any one of claims 1 to 9, comprising the following construction steps: Step 1: At the bottom of the cofferdam base, use plum blossom piles to drive several steel bars into the soil layer at intervals, and reserve a height of 200mm-300mm; Step 2: a first anti-seepage isolation structure and a second anti-seepage isolation structure are provided at the reserved end positions of the steel bars; Step 3, a first riprap slope protection structure is arranged on the upper end of the first anti-seepage isolation structure, and a second riprap slope protection structure is arranged on the upper end of the second anti-seepage isolation structure; Step 4: Lay a number of coarse sand bags on the first side of the first riprap slope protection structure, and arrange a reinforced rockfill layer on the second side to complete the construction.

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