A deep-water high-angle bare rock cofferdam and construction method

Abstract

The present invention relates to the technical field of underwater structures, and more specifically, it relates to a deep-water large-angle bare rock cofferdam and a construction method, comprising a cofferdam body. During the construction process, the side of the cofferdam body facing upstream is the upstream side, the side of the cofferdam body facing away from the shore is the back shore side, and the side of the cofferdam body facing the shore is the shore side. A water flow guiding structure is arranged on the upstream side of the cofferdam body, and the water flow guiding structure guides the water flow to the side of the cofferdam body facing the shore. The deep-water large-angle bare rock cofferdam and the construction method of the present invention can guide the water flow flowing to the upstream side of the cofferdam body to the shore side, thereby alleviating the lateral pressure caused by the inclined riverbed, reducing the bearing capacity required for the shore side of the cofferdam body, and avoiding the cofferdam from being easily deformed or displaced.

Description

Technical Field

[0001] The invention relates to the technical field of underwater structures, in particular to a deep-water large-angle bare rock cofferdam and a construction method thereof. Background Art

[0002] Cofferdam refers to a temporary maintenance structure built in the construction of permanent water conservancy facilities in water conservancy projects. Its function is to prevent water and soil from entering the construction site of the building so that drainage can be done in the cofferdam, foundation pits can be excavated, and buildings can be built. It is generally used in hydraulic structures. Except as part of a formal building, the cofferdam is generally dismantled after use.

[0003] For example, in the construction of a cross-river bridge, in order to build the bridge piers, it is necessary to first build a cofferdam in the river. Since the riverbed conditions at the bottom of the river are often complex and diverse, the cofferdam usually has various forms, one of which is a large-angle bare rock cofferdam based on deep water areas. Bare rock means that the riverbed in the cofferdam construction area is an exposed rock surface and is not covered by mud and sand. Traditional piling reinforcement measures are difficult to implement on such hard rocks, so special drilling, anchoring or other reinforcement methods are usually required to ensure the stability of the cofferdam. The large inclination angle refers to the large inclination angle of the riverbed in the cofferdam construction area, which usually tilts from the river bank to the center of the river. This requires the side of the cofferdam facing the bank to have a higher bearing capacity to withstand the lateral pressure from the inclined riverbed, otherwise it will easily cause the cofferdam to deform or move. Summary of the invention

[0004] In order to alleviate the lateral pressure caused by the inclined riverbed and avoid the cofferdam from being easily deformed or displaced, the present application provides a large-angle bare rock cofferdam based on deep water areas and a construction method.

[0005] In the first aspect, the present invention provides a deep-water large-angle bare rock cofferdam, which adopts the following technical solution:

[0006] A deepwater high-angle bare rock cofferdam comprises a cofferdam body, an upstream surface of which is provided with a water flow guiding structure, which guides the water flow to the side of the cofferdam body facing the shore.

[0007] Preferably, the cross-section of the water flow guiding structure is a right triangle, and the water flow guiding structure includes a first right-angled surface, a second right-angled surface and an inclined surface connected between the first right-angled surface and the second right-angled surface, the first right-angled surface is parallel to the upstream surface of the cofferdam body, the second right-angled surface is parallel to the back shore surface of the cofferdam body, and the inclined surface is inclined toward the shore surface of the cofferdam body.

[0008] Preferably, the water flow guiding structure includes a connecting plate, a straight plate, and an inclined plate that are connected to each other. The connecting plate is connected in parallel to the upstream surface, the straight plate is vertically connected to the connecting plate, and the straight plate is connected to one end of the connecting plate facing away from the shore. The inclined plate is connected between the outer end of the straight plate and the end of the connecting plate facing the shore.

[0009] Preferably, the connecting plate includes a fixed plate and a movable plate. The fixed plate is connected to the upstream surface of the cofferdam body, the movable plate is connected to the straight plate and the inclined plate, and a plurality of telescopic cylinders are connected between the fixed plate and the movable plate. The telescopic cylinders expand and contract along the water flow direction, and springs that deform along the expansion and contraction direction are arranged inside the telescopic cylinders.

[0010] Preferably, reinforcing rods are arranged inside the water flow guiding structure. The reinforcing rods include a plurality of first reinforcing rods and a plurality of second reinforcing rods. The plurality of first reinforcing rods are connected between the inner sides of the straight plate and the inclined plate. The plurality of first reinforcing rods are parallel to each other and parallel to the upstream surface of the cofferdam body. The plurality of second reinforcing rods are respectively connected between two adjacent first reinforcing rods. The plurality of second reinforcing rods are parallel to each other and parallel to the back shore surface of the cofferdam body.

[0011] Preferably, a water level monitoring system is arranged on the cofferdam body. The water level monitoring system includes a water level sensor, a controller, and an alarm that are connected by signals in sequence. A water level threshold H is set inside the controller. When the water level sensor monitors that the current water level exceeds the water level threshold H, the controller controls the alarm to give an alarm.

[0012] Preferably, the water level monitoring system receives meteorological data to obtain the rising amount of the tide during the rising tide period of the day. The calculation of the water level threshold H is as follows: During non-rising tide periods, the water level threshold H = standard value h; during rising tide periods, the water level threshold H = standard value h + rising amount c.

[0013] Preferably, the water level monitoring system calculates the rising amount of the water level per unit time to obtain the current water level rising rate. A water level rising rate threshold x is set inside the water level monitoring system. A corresponding adjustment value b is set for the water level rising rate threshold x. When the water level rising rate exceeds the water level rising rate threshold x, the calculation of the water level threshold H is as follows: Water level threshold H = standard value h - adjustment value b; The priority of adjusting the water level threshold H according to the water level rising rate x is higher than the priority of adjusting the water level threshold H according to the rising tide period.

[0014] Preferably, the water level rising rate threshold x includes x1 and x2, where x1 < x2. Among them, x1 is used for non-rising tide periods, and x2 is used for rising tide periods.

[0015] In a second aspect, the present invention provides a construction method for a deepwater large-angle bare rock cofferdam, which adopts the following technical solution:

[0016] A construction method for a deepwater high-angle bare rock cofferdam comprises the following steps:

[0017] A water flow guiding structure is arranged on the upstream surface of the cofferdam body, so that the water flow guiding structure guides part of the upstream water flow to the shore side of the cofferdam body; the water level sensor is arranged on the cofferdam body and connected to the water level monitoring system, so that the water level monitoring system issues an early warning when it detects that the current water level exceeds the water level threshold H.

[0018] The beneficial effects of the present invention are:

[0019] 1. The water flow guiding structure can guide the water flowing to the upstream surface of the cofferdam body to the shore surface, thereby alleviating the lateral pressure caused by the inclined riverbed, reducing the bearing capacity required by the shore surface of the cofferdam body, and avoiding the cofferdam from being easily deformed or displaced;

[0020] 2. When the water flow guide structure faces the impact force of the water flow, it can effectively absorb the impact force through the expansion and contraction of the telescopic tube and the deformation of the spring, thereby reducing the structural stress and extending the service life of the structure;

[0021] 3. When the water level sensor detects that the current water level exceeds the water level threshold H, the controller controls the alarm to sound an alarm to remind relevant personnel to take corresponding measures. In addition, the water level threshold H in the water level monitoring system can rise with the arrival of the high tide period to avoid the alarm being too sensitive and reduce false alarms. Furthermore, when encountering extreme weather or unexpected conditions upstream, the water level threshold H in the water level monitoring system can always be reduced in time as the water level rises too fast to avoid being unable to respond to emergencies in time. In addition, in the process of the water level monitoring system judging whether the water level rise rate exceeds the water level rise threshold x, the influence of the water level rise factor brought by the high tide period can be eliminated, so that the water level monitoring system can make a more accurate judgment on whether the water level rise rate is too fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a transverse cross-sectional view of a bare rock cofferdam with a large dip angle in a deep water area according to an embodiment of the present application;

[0023] Figure 2 is a longitudinal cross-sectional view of the cofferdam body in water in an embodiment of the present application;

[0024] Figure 3 It is a schematic diagram of the framework of the water level monitoring system in the embodiment of the present application.

[0025] Explanation of the accompanying reference numerals: 1. cofferdam body; 11. shore surface; 12. back shore surface; 2. connecting plate; 21. fixed plate; 22. movable plate; 3. straight plate; 4. inclined plate; 5. telescopic cylinder; 61. first reinforcing rod; 62. second reinforcing rod. DETAILED DESCRIPTION

[0026] The following will be combined with the attached Figure 1 -Attached Figure 3 The present invention is further illustrated by the following embodiments.

[0027] This embodiment discloses a deep-water area high-angle bare rock cofferdam.

[0028] Reference Figure 1 and Figure 2 , based on the deep-water area high-angle bare rock cofferdam, it includes a cofferdam body 1, with the side of the cofferdam body 1 facing upstream as the upstream face, the side of the cofferdam body 1 facing away from the shore as the back shore face 12, and the side of the cofferdam body 1 facing the shore as the shore face 11, and a water flow guiding structure is provided on the upstream face of the cofferdam body 1, and the water flow guiding structure guides the water flow to the side of the cofferdam body 1 facing the shore. To achieve the above effect, the cross-section of the water flow guiding structure is a right triangle, and the water flow guiding structure includes a first right-angled surface, a second right-angled surface, and an inclined surface connected between the first right-angled surface and the second right-angled surface, wherein the first right-angled surface is parallel to the upstream face of the cofferdam body 1, and the second right-angled surface is parallel to the back shore face 12 of the cofferdam body 1, so that the inclined surface is inclined to the shore face 11 of the cofferdam body 1. Specifically, the water flow guiding structure includes interconnected connecting plates 2, straight plates 3 and inclined plates 4, the connecting plates 2 are connected in parallel to the upstream surface, the straight plates 3 are connected vertically to the connecting plates 2, and the straight plates 3 are connected to the end of the connecting plates 2 facing away from the shore, and the inclined plates 4 are connected between the outer end of the straight plates 3 and the end of the connecting plates 2 facing the shore, thereby forming a water flow guiding structure with a right triangle cross section. Through the above arrangement, the water flow guiding structure can guide the water flow flowing to the upstream surface of the cofferdam body 1 to the shore surface 11, thereby alleviating the lateral pressure caused by the inclined riverbed, reducing the bearing capacity required for the shore surface 11 of the cofferdam body 1, and avoiding the cofferdam from being easily deformed or displaced.

[0029] Reference Figure 1 The connecting plate 2 includes a fixed plate 21 and a movable plate 22. The fixed plate 21 is connected to the upstream surface of the cofferdam body 1. The movable plate 22 is connected to the straight plate 3 and the inclined plate 4. A plurality of telescopic cylinders 5 are connected between the fixed plate 21 and the movable plate 22. The telescopic cylinders 5 are telescopic along the water flow direction. Furthermore, a spring that deforms along the telescopic direction is arranged inside the telescopic cylinder 5. Through the above arrangement, when the water flow guide structure faces the impact force of the water flow, the impact force can be effectively absorbed by the telescopic cylinder 5 and the deformation of the spring, thereby reducing the structural stress and extending the service life of the structure.

[0030] Reference Figure 1 In order to improve the structural strength of the water flow guide structure, a reinforcing rod is arranged in the water flow guide structure, and the reinforcing rod includes a plurality of first reinforcing rods 61 and a plurality of second reinforcing rods 62, wherein the plurality of first reinforcing rods 61 are connected between the inner side of the straight plate 3 and the inner side of the inclined plate 4, the plurality of first reinforcing rods 61 are parallel to each other and parallel to the upstream surface of the cofferdam body 1, the plurality of second reinforcing rods 62 are respectively connected between two adjacent first reinforcing rods 61, the plurality of second reinforcing rods 62 are parallel to each other and parallel to the back shore surface 12 of the cofferdam body 1, and finally, through the arrangement of the first reinforcing rods 61 and the second reinforcing rods 62, the structural strength of the water flow guide structure can be effectively improved, and the water flow guide structure can be prevented from being easily damaged by continuous water flow impact.

[0031] Reference Figure 3 In order to improve safety, it is necessary to monitor the water level around the cofferdam body 1 to prevent the water level from exceeding the height of the cofferdam body 1. Therefore, in this embodiment, a water level monitoring system is provided on the cofferdam body 1. The water level monitoring system includes a water level sensor, a controller and an alarm connected in sequence. A water level threshold H is provided in the controller. When the water level sensor detects that the current water level exceeds the water level threshold H, the controller controls the alarm to sound an alarm to remind relevant personnel to take corresponding measures.

[0032] The water level of rivers will be affected by tidal forces, especially in estuary areas close to the ocean, which causes the water level around the cofferdam body 1 to be higher during high tide. If the water level threshold H remains unchanged, it is easy to cause the warning of the water level monitoring system to be more sensitive and produce false alarms. For this reason, in this embodiment, the water level monitoring system also receives meteorological data to obtain the tidal volume during the high tide period of the day. The water level threshold H is calculated as follows: in non-high tide periods, the water level threshold H = standard value h, and in high tide periods, the water level threshold H = standard value h + tidal volume c, so that the water level threshold H in the water level monitoring system can rise with the arrival of the high tide period, avoiding the alarm being too sensitive and reducing false alarms.

[0033] When encountering extreme weather or unexpected situations upstream, it may cause the water level around the cofferdam body 1 to rise rapidly. If the water level threshold H of the water level monitoring system remains unchanged, it is easy to make the warning of the water level monitoring system relatively slow, resulting in the inability to respond to emergencies in a timely manner. Therefore, in this embodiment, the water level monitoring system also calculates the amount of water level rise per unit time to obtain the current water level rise rate. Moreover, a water level rise rate threshold x is set in the water level monitoring system, and there is an adjustment value b corresponding to the water level rise rate threshold x. When the water level rise rate exceeds the water level rise rate threshold x, the calculation of the water level threshold H is as follows: water level threshold H = standard value h - adjustment value b. And the priority of adjusting the water level threshold H according to the water level rise rate x is higher than the priority of adjusting the water level threshold H according to the flood tide period, that is: the formula of water level threshold H = standard value h - adjustment value b will overwrite the formula of water level threshold H = standard value h + flood tide volume c, so that the water level threshold H in the water level monitoring system can always drop in time as the water level rise rate is too fast, avoiding the inability to respond to emergencies in a timely manner.

[0034] The water level rise rate threshold x includes x1 and x2, where x1 < x2. Among them, x1 is used for non-flood tide periods, and x2 is used for flood tide periods. The purpose is to: in the process of the water level monitoring system judging whether the water level rise rate exceeds the water level rise threshold x,尽可能排除涨潮时段自带的水位上升因素带来的影响,使得水位监测系统对水位上升速率是否过快做出更准确的判断。

[0035] This embodiment also discloses a construction method based on a cofferdam in deep water with a large dip angle of bedrock.

[0036] Refer to Figures 1 to 3 , the construction method based on the cofferdam in deep water with a large dip angle of bedrock includes the following steps:

[0037] A water flow guiding structure is arranged on the upstream surface of the cofferdam body 1 to guide part of the upstream water flow to the shore side of the cofferdam body 1; a water level sensor is arranged on the cofferdam body 1 and connected to the water level monitoring system, so that the water level monitoring system gives an alarm when it monitors that the current water level exceeds the water level threshold H.

[0038] The above are all preferred embodiments of the present invention, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A deep-water high-angle bare rock cofferdam, characterized by: It includes a cofferdam body (1), and a water flow guiding structure is arranged on the upstream surface of the cofferdam body (1), and the water flow guiding structure guides the water flow to the side of the cofferdam body (1) facing the shore; The cross-section of the water flow guiding structure is a right triangle. The water flow guiding structure includes a first right-angled surface, a second right-angled surface, and an inclined surface connecting between the first right-angled surface and the second right-angled surface. The first right-angled surface is parallel to the upstream surface of the cofferdam body (1), the second right-angled surface is parallel to the back shore surface (12) of the cofferdam body (1), and the inclined surface is inclined towards the shore side surface (11) of the cofferdam body (1); The water flow guiding structure includes a connecting plate (2), a straight plate (3), and an inclined plate (4) connected to each other. The connecting plate (2) is parallelly connected to the upstream surface. The straight plate (3) is perpendicularly connected to the connecting plate (2), and the straight plate (3) is connected to the end of the connecting plate (2) facing away from the shore. The inclined plate (4) is connected between the outer end of the straight plate (3) and the end of the connecting plate (2) facing the shore; The connecting plate (2) includes a fixed plate (21) and a movable plate (22). The fixed plate (21) is connected to the upstream surface of the cofferdam body (1). The movable plate (22) is connected to the straight plate (3) and the inclined plate (4). A plurality of telescopic cylinders (5) are connected between the fixed plate (21) and the movable plate (22). The telescopic cylinders (5) expand and contract along the water flow direction, and springs that deform along the expansion and contraction direction are arranged in the telescopic cylinders (5); A water level monitoring system is arranged on the cofferdam body (1). The water level monitoring system includes a water level sensor, a controller, and an alarm that are sequentially connected by signals. A water level threshold H is set in the controller. When the water level sensor monitors that the current water level exceeds the water level threshold H, the controller controls the alarm to give an alarm; The water level monitoring system receives meteorological data and obtains the rising tide volume during the rising tide period of the current day. The calculation of the water level threshold H is as follows: during the non-rising tide period, the water level threshold H = standard value h; during the rising tide period, the water level threshold H = standard value h + rising tide volume c; The water level monitoring system calculates the water level rising amount per unit time to obtain the current water level rising rate. A water level rising rate threshold x is set in the water level monitoring system. There is an adjustment value b corresponding to the water level rising rate threshold x. When the water level rising rate exceeds the water level rising rate threshold x, the calculation of the water level threshold H is as follows: the water level threshold H = standard value h - adjustment value b; the priority of adjusting the water level threshold H according to the water level rising rate x is higher than the priority of adjusting the water level threshold H according to the rising tide period; The water level rising rate threshold x includes x1 and x2, where x1 < x2. Among them, x1 is used for the non-rising tide period, and x2 is used for the rising tide period.

2. The deep-water high-angle bare rock cofferdam according to claim 1 is characterized by: The water flow guide structure is provided with reinforcing rods, which include a plurality of first reinforcing rods (61) and a plurality of second reinforcing rods (62). The plurality of first reinforcing rods (61) are connected between the inner side of the straight plate (3) and the inner side of the inclined plate (4). The plurality of first reinforcing rods (61) are parallel to each other and to the upstream surface of the cofferdam body (1). The plurality of second reinforcing rods (62) are respectively connected between two adjacent first reinforcing rods (61). The plurality of second reinforcing rods (62) are parallel to each other and to the back shore surface (12) of the cofferdam body (1).

3. A construction method for a deep-water high-angle bare rock cofferdam, used for the deep-water high-angle bare rock cofferdam as claimed in claim 1, characterized in that: The following steps are involved: A water flow guiding structure is arranged on the upstream surface of the cofferdam body (1), so that the water flow guiding structure guides part of the upstream water flow to the shore side of the cofferdam body (1); and a water level monitoring system is arranged on the cofferdam body (1), so that the water level monitoring system issues an early warning when it detects that the current water level exceeds a water level threshold value H.

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