Construction scheme of dredging project (I)

(1) Dredging, dewatering and drainage of pipeline

The sewage in the inspection well is discharged to sludge at the bottom of the well by mud pump. The pipeline to be dredged is segmented, and the segmentation method is allocated according to the pipe diameter and length, and there is a section between two inspection wells with the same pipe diameter.

(2) pipeline dredging to dilute the sludge

High-pressure waterwheel pours water into the chamber of two segmented inspection wells, and dredgers are used to mix the sludge in the inspection wells and sewage pipes to dilute the sludge; The manpower should cooperate with the machinery to continuously stir the sludge until it is diluted into the water.

(3) pipeline dredging and dirt suction

The sludge in the two inspection wells is sucked clean by a dirt suction truck, and a small amount of sludge left in the two inspection wells impacts the sludge at the bottom of the well with a high-pressure water gun, which is diluted again, and then the suction is finished.

(4) Dredging and sewage interception of pipelines

Set a plug to plug the water inlet of the well chamber at the first working section from top to bottom, and then block the outlet of the downstream inspection well and other pipeline openings, leaving only the inlet and outlet of this section of pipeline.

(5) High-pressure cleaning vehicle dredging

Use the high-pressure cleaning vehicle to dredge the pipeline, extend the hose of the high-pressure cleaning vehicle into the lower part of the upstream inspection well, aim the water nozzle at the pipeline to spray water, and the sewage pipeline downstream inspection well continuously sucks the indoor sludge.

(6) pipeline dredging and ventilation

Before the construction workers enter the inspection well, the oxygen in the atmosphere must enter the inspection well or be ventilated with a blower to measure the oxygen content in the well, and the construction workers must wear safety belts, gas masks and oxygen tanks when entering the well.

(7) Dredging

After organizing the safety measures for the construction personnel before running down the well, manually sort out the remaining bricks, stones, some sludge and other residues in the inspection well until the sorting is finished.

then, according to the above explanation, the downstream sewage inspection wells will be dredged one by one, and the inspection wells that are arranged first in the upstream will be blocked during the dredging time to prevent the upstream sludge from flowing into the pipeline or into the upstream inspection wells and pipelines when the pipeline is filled with water during the downstream construction time.

Construction scheme of dredging project (II)

I. Compilation basis

1. Task of special environmental improvement project in * * issued by Chengdu City Appearance and Environment Bureau

2. Task book of dredging and clearing silt issued by Chengdu Water Resources Bureau

3. Relevant technical and safe operation specifications

4. Time limit: mid-May-end of May

. General situation of the project:

This project is a part of the river silt removal construction of the special urban environment improvement project in * *. In order to ensure that the improvement project achieves the expected effect, dredging is carried out to clean the river bed to meet the design requirements of river bed elevation and flood control and navigation requirements, and to give the people a clean and clean river. This removal is a professional dredging of the river section.

this project is for dredging silt in the channel of Diandi River, with a total length of 5,7 m from the second ring road to the third ring road of Diandi River. The average width of the Diandi River in this section is 1.M, and the banks are vertical embankments with H=3.5M high. The average width of silt in the river channel is 5.M and the depth is .8M.

3. Three links, one leveling and temporary water supply

: Use the water source of management facilities along the river to solve the drinking water problem.

electricity: electricity for lighting and drainage (or street lamp power supply on the river bank) is set up by using the power supply of the nearest unit for night construction.

Road: transportation is organized by using the channels on both sides of the river to facilitate the operation of vehicles transporting silt. However, at present, the river protection channels on both sides of the river have not been completely connected, and there are obstacles blocking the river protection channels in some places. We must use the river protection channel to facilitate transportation when removing river silt, so these obstacles must be removed, and the specific volume of obstacles will be measured again when entering the site for construction.

temporary facilities: because the construction period of this project is short and the length along the construction site is long, our company considers not to build temporary facilities on the construction site. Instead, rent residential houses in the neighborhood instead of temporary facilities.

IV. Personnel organization

To ensure that the project is completed with good quality and quantity according to the time limit required by Chengdu City Appearance and Environment Bureau and Chengdu Water Resources Bureau. For this reason, our company has set up a dredging project headquarters headed by Yu Xianglin, the company manager, with Zhou Jinhua, the deputy manager in charge of logistics, and Yuan Zhengxu, the manager of the mechanical department in charge of mechanical equipment, as the deputy heads to be responsible for the implementation of the project.

V. Construction measures

1. Division of construction sections: Due to the long distance along the river, dredging can be carried out in 3-4 sections according to the dredging quantity and construction period requirements, and each section is provided with a river-crossing lane. All the excavated earthwork shall be transported abroad.

2. Construction measures:

① Drainage:

Dig a longitudinal drainage ditch on the outer side of the river silt to make the water return to the tank. Earthwork is piled on the edge of the trough to form a ridge, so that a small amount of river water can be drained through the trough. When dredging, clean it from top to bottom or from bottom to top respectively.

② dredging:

The dredging section of the river is located between the Second Ring Road and the Third Ring Road, and vehicles can pass by during the day and at night. Therefore, it is necessary to arrange the dredging construction reasonably according to the amount of silt and the construction period. There are no large traffic roads along the river, and the road conditions in some sections are poor, which makes it inconvenient for earth-moving vehicles to pass and the dredging efficiency is not high. Therefore, it is necessary to consider increasing transport vehicles and night construction. When dredging the river, the silt in the river shall be dredged and transported ashore manually, and then the dredger, loader and car shall be used to clear and dredge the earthwork. When removing silt, immediately send someone to clean up the scattered earthwork on the road, so as to give the surrounding citizens a good living environment.

There is a green belt slope on the top of some embankment sections of this river, and only the transportation machinery and excavation machinery can travel on the top of the slope, and they can't go down into the river to dredge silt. Therefore, the river silt in this section can only be dredged manually, then transported to the top of the green belt slope manually, and finally transported out by transportation machinery. Therefore, this part of the silt dredging unit quantity price is higher than the mechanical direct excavation freight. According to our measurement, this part of the engineering quantity accounts for 4% of the total engineering quantity. In other river sections, we consider using excavation machinery to directly open the river channel for dredging silt, but there is no down-river lane in the whole section of the Diandi River, so we consider using silicon blocks to lay temporary down-river lanes at appropriate positions of the Diandi River. According to the site situation, there are three places for Xiahe Horse Road. After the silt in the river bed has been removed, the silicon blocks will be removed manually to go down the river path.

VI. Dumping yard

In order to cooperate with the smooth removal of the dredged riverbed silt, our company will contact the dumping yard near the Third Ring Road. The dumping site is about 6~8KM away from the dredging site. After the transport vehicle enters the traffic road, the road traffic is smooth. A bulldozer is equipped to knock down the field to facilitate the bulldozing.

VII. Cleaning and cleaning

According to the relevant regulations of Chengdu on the prevention and control of dust, in order to ensure that the dredging of the river will not affect the surrounding environment at the same time, the cleaning and cleaning work should be done well in the dredging process, and the person in charge should be responsible. Each construction section is equipped with 2 migrant workers respectively. Responsible for protecting the facilities formed along the river and laying straw mats at the exit; Be on duty and organize traffic at intersections. Each earth-moving vehicle can only be released after cleaning the wheels and carriages, so as to ensure a clean and comfortable environment for the people every day.

VIII. Safety measures

Set guardrails and warning signs at major traffic exits, assign special personnel to be on duty, and organize traffic at intersections. Do a good job in lighting and safety red light in the construction river section, and carry out safety education for relevant drivers, abide by traffic safety laws and regulations, and it is strictly forbidden to drink and drive.

IX. Mechanical equipment

Two crawler excavators EX2 2

Loaders ZL5 2

3 5t dump trucks

X. Staffing

2 general workers

Construction scheme of dredging project (3)

I. Overview:

Cleaning garbage when the river course in XX is uncertain.

construction period is 12 days: 1 day for preparation, and it is planned that the dredging length will be 2m every day, and the river bottom will be leveled and the cofferdam will be dismantled for 1 day.

2. Scheme:

Find out the inflow of water in the upper reaches of the river in normal period, the specific position and trend of infrastructure such as bridges and pipelines along the way, and the depth of sediment deposition in the river, organize manpower and machinery according to the dredging workload and time limit for a project, and consider the requirements of flood control and flood control to prepare materials.

1. Organization:

The river course realignment project is close to the old river course, and there are large-scale construction machinery on the construction site, which can be used for river dredging. It is planned to use multiple crawler excavators to carry out dredging in groups and sections. In the process of dredging, it is necessary to maintain the normal water supply of the old Weihe River, and half of the dredging and half of the running water; First dredge the south half of the river, and then dredge the north river.

2. Cofferdam:

A 5mm thick brick masonry cofferdam with two movable gates is set at the downstream of the river, which is flush with the top surface of the abutment foundation and can also be used as the cofferdam when the alignment project is connected with the old river (the gates are 3m wide and of wooden structure). The downstream cofferdams are set in sections according to the dredging length, and are planned to be set on the south side of the Fishing Association and downstream of Tangzhuang Bridge respectively, and the height should be .7 meters above the water surface. The downstream cofferdam adopts soil structure, and the outer side is covered with waterproof material (such as wide striped cloth).

3. Drainage:

After the completion of the cofferdam construction, sewage pumps will be used to drain the accumulated water in the river channel to the downstream river channel of the cofferdam, and longitudinal water collecting ditches will be excavated along the bottom edge of the old river channel to collect the accumulated water in the river channel in front of the downstream cofferdam. Excavate a sump in the upstream of the cofferdam, and use a high-power sewage pump to discharge the accumulated water to the downstream of the cofferdam.

4. Dredging:

Three excavators are used as a group to form a ladder queue. An excavator at the bottom of the river is in front, and the sediment at the bottom of the river is cleaned to the south while excavating, and the sediment is placed above the slope as much as possible, and at the same time, a catchment ditch with a depth of about 5cm is excavated at the bottom line of the south side of the river; The second one is above the slope, and the sludge dug by the first excavator and the roots of turf on the slope are cleared into the beach on the south side of the river, and the third one is at the last side, and the sludge dug by the second excavator is collected.

the dredging of the southern half is completed, and the silt in the north river channel is cleaned by the same method. At this time, the accumulated water has been concentrated in the southern half of the river channel, so it is not necessary to dig a longitudinal catchment ditch at the bottom line of the north river. After dredging, the river bottom will be leveled.

5. Cleaning:

The sludge in the beach is dried and dehydrated, and the sludge is transported to the owner's place by a well-sealed transport vehicle.

6. Dismantling of cofferdam:

The cofferdam is reserved with movable gates, which can meet the requirement of normal water flow. It will be dismantled after the completion of the Weihe River realignment project and the old river channel, so as to restore the smooth flow of the river channel. The downstream cofferdam can be dismantled after the dredging work in the upstream of the cofferdam is completed, and the river channel can be restored.

7. Flood control and flood control:

Upon receiving the flood warning information, immediately stop dredging, mobilize for flood control, start the emergency plan and make good preparations for flood control. After receiving the exact information, all construction machinery shall be evacuated from the river within 3 minutes, and the downstream cofferdam shall be dredged to ensure the smooth flow of the river.

III. Precautions:

1. Cooperate with the owner to complete relevant procedures before dredging;

2. There are some crops in the range of dredging working face along the way (such as slope and beach), which should be removed in advance;

3. The sludge should be cleared away from the site when it is temporarily piled up on the beach, so that the transport vehicles can pass through the temporary road;

4. The original traffic facilities need to be protected or protected for dredging under roads and bridges;

5. Investigate the distribution trend, buried depth and specific location of pipelines (such as national defense optical cable, electric power, communication, water supply, gas and other pipelines) in the dredging river section, make records, and make obvious marks on the spot;

6. Take leak-proof measures when transporting sludge, and drive away from the clear vehicles to prevent road pollution;

7. Strengthen the protection of green vegetation on both sides of the river, and do not maliciously destroy trees on both sides of the river;

8. The isolation fence is dredged and restored to its original state.

4. Personnel and machinery:

1. Personnel arrangement: 4 managers, 6 skilled workers, 16 general workers and 4 mechanical operators.

2. Main machinery: 6 excavators, 12 dump trucks, 2 loaders and 2 bulldozers.

3. 6 sets of sewage pumps and 4 sets of submersible pumps.