Problems in the hydraulic structure of sluices

According to the survey of the large and medium-sized sluices that have been reinforced and reformed in recent years, the hydraulic structure of the sluice chamber mainly has the following problems:

• There is no hoist room, which does not meet the requirements of protecting hoist equipment and flood prevention.

• The concrete of the gate pier spalled and carbonized due to freezing and thawing, and the local gate pier was concrete without or less reinforcement.

• The gate pier is a mortar and stone structure, and the gate slot needs to be rebuilt when the gate is replaced.

• The side piers, upstream and downstream wing walls have insufficient water and soil retaining height.

• The structure does not meet the seismic requirements.

Reinforcement treatment plan

After the opening and closing machine room was added, the strength of the original bent column did not meet the design requirements, and the bent column must be demolished and rebuilt, and the steel bars of the bent column were implanted into the original gate pier.

The piers are made of unreinforced or less-reinforced concrete, the surface is eroded and carbonized, and the strength does not meet the design requirements. On both sides of the original gate piers, combined with concrete denudation and carbonization treatments, rebars are planted on the sluice bottom plate to be integrated with the original gate piers to increase strength.

The pier is a mortar and masonry structure, and its strength does not meet the design requirements. Reinforcement measures adopt demolishing and rebuilding, and re-pouring the gate piers by planting steel bars in the gate bottom plate.

When replacing the gate and rebuilding the gate slot, the side rails and bottom rails of the gate must be embedded, and structural ribs must be implanted in the gate bottom plate and pier to fix the side rails and bottom rails.

According to the reinforcement design plan, some control gate side piers, upstream and downstream wing walls are not high enough to retain water and soil. Reinforcing steel bars in the original concrete and re-pouring reinforced concrete to meet the requirements of operation and management.

Reinforcing glue technology

1- Characteristics of reinforcement and reconstruction project

(1) The construction period is tight. The construction period of the control gate project generally begins at the end of the flood of the year, and the flood control requirements must be met by 31FI of the following year, and the construction period is short.

(2) The construction of the reinforcement and renovation project is difficult. The original structure must not be destroyed, the strength of the new structure must be ensured, and the two must be closely integrated to form a unified whole.

(3) The area of planting bars is large, and there are many structural parts of planting bars, especially the planting bars of pier and bottom plate affect the safety of the entire lock chamber.

2- The advantages of the planting glue technology The planting glue technology has a short length of anchored steel bars, shallow drilling, avoiding traditional chiseling; too large a hole diameter, which will reduce the strength of the original structure. Adhesive strength 3d reaches the design strength, the application speed is fast, the construction period is short, and the investment is saved.

3- Construction technology of planting bar glue technology

(1) Base surface cleaning: the obstacles and scum on the construction surface should be cleaned up.

(2) Positioning and laying-off: According to the requirements of the design drawings, the laying-off and positioning should be carried out, and the allowable deviation of hole position is 5mm.

(3) Drilling: In the design position, choose electric hammer or water drill to make holes according to the design requirements of the hole diameter and hole depth.

(4) Hole cleaning: Use a high-pressure air pump to blow off the scum in the hole, and clean it with cotton silk soaked with acetone to meet the requirements of water-free, oil-free, clean and dry planting.

(5) Reinforcing steel treatment: Grind and remove the rust of the reinforcing steel embedded in the concrete, and clean it with cotton wool soaked in acetone or other cleaning agents. If the steel is corroded seriously, soak it with hydrochloric acid. (6) Glue filling: Pour the glue into a clean container and stir it completely by manual or electric tools to ensure the uniformity of the structural glue. Inject the adjusted structural glue into the hole of the planting bar. The glue injection capacity in the hole must be greater than 50%.

(7) Implanted steel bars: slowly rotate the cleaned steel bars into the anchoring holes, and exhaust the air in the holes to meet the design depth requirements.

(8) Curing and curing: The planting bar glue can be cured naturally at room temperature (-5℃～40℃). Disturbance is strictly prohibited within 24h, and it can bear the design load after 72h.

Application of planting bar glue technology in the reinforcement and reformation of control gate

1- Main problems existing in hydraulic structure

After on-site safety inspection and engineering safety review, the hydraulic structure of the gate currently has the following problems:

(1) The anti-seismic standard does not meet the requirements of the current specifications: only the doorway of the middle pier is 150 reinforced concrete, and the other parts are 100 mortar masonry stone wall and mortar rubble core filling. The door slot of the side pier adopts 150 reinforced concrete structure, and the other parts are 150 plain concrete structure.

(2) The original construction quality was poor. During the construction of frame bridges and frame piers, the concrete surface had serious honeycombs, pockmarked surfaces, and holes, and the thickness of the reinforced protective layer was uneven, and there were even many exposed main bars.

(3) The reinforced concrete gate has serious concrete carbonation, and serious corrosion of steel wire mesh and steel bars; the opening and closing models are obsolete, with low operating efficiency and high energy consumption.

2- Hydraulic structure reinforcement scheme

The Fuxin River Control Gate is located at the junction of Shandong and Surrey provinces. It is a boundary project and involves many sensitive factors. Therefore, the original gate design was approved by the Ministry of Water Resources. Therefore, the main technical indicators of the gate reinforcement and reconstruction this time remain unchanged. After a comprehensive technical and economic comparison of the schemes, the demolition and reconstruction scheme above the bottom plate was adopted, the frame bridge was removed and reconstructed, the frame pier was removed and reconstructed, the middle pier was removed and reconstructed, and the side piers and bottom pier were reinforced.

3- Application of planting glue technology

(1) Reinforcing bar location According to the existing problems and reinforcement plan of the Fuxin River Control Gate, the main rebar planting locations include:

①The pier in the gate is a mortar and masonry structure, demolished and reconstructed, and re-poured the gate pier by planting steel bars in the gate bottom plate.

②When replacing the gate and side piers to rebuild the gate groove, the side rails and bottom rails of the gate must be embedded in the gate bottom plate and piers to fix the side rails and bottom rails.

③The retaining height of the side piers and the upstream and downstream wing walls is not enough, so the original concrete is implanted with steel bars and the reinforced concrete is re-poured to meet the requirements of operation and management.

This article focuses on the application of the technology of planting reinforcement glue in the joint part of the pier and the bottom plate of the control gate. The middle pier is 7.5m long along the water flow and 1.0m thick. According to the calculation results of the pier structure, it is equipped with grade II steel bars with a diameter of 20mm and a spacing of 200mm. A total of 4072 steel bars are required to be planted in the middle pier of the Fuxin River Control Gate.

Benefit Analysis

(1) The construction period can be shortened. The diameter of the drill hole of the planting glue process is 28mm, and the depth of the hole is 40era. The curing time is 3d and it can be transferred to the next process. The construction period was saved by 11 days, which laid a good foundation for grabbing the construction period and meeting the pre-flood conditions.

(2) It can save a lot of investment. The total cost of planting 4072 roots with planting glue is RMB 189,800. From the analysis of the material cost alone, the rubber planting process cost 39,200 yuan more.

(3) The structural strength of the original gate bottom plate is not affected. Factors such as the micro-swelling stress of the swelling mortar, the larger diameter of the drill hole, and the deeper hole in the traditional bar planting process will adversely affect the original structure. The planting rubber technology, the drilling diameter and hole depth are far smaller than the traditional technology, the adhesive brake is strongly adsorbed with the concrete, the damage to the existing structure is naturally much smaller, and the value of this aspect is immeasurable.