(1) Pipeline dredging, drainage and drainage
The sewage from the inspection well is discharged into the mud at the bottom of the well by a mud pump. The pipeline to be dredged is segmented, and the segmentation method is distributed according to the pipe diameter and length, and there is a section between two inspection wells with the same pipe diameter.
(2) Pipeline dredging and sludge dilution
High-pressure waterwheel injects water into the well chamber from two segmented inspection wells, and the sludge in the inspection wells and sewage pipes is mixed with a dredging machine to dilute the sludge; Manpower should cooperate with machinery to continuously stir sludge until it is diluted into water.
(3) Pipeline dredging and pollution absorption
The sludge in the two inspection wells is sucked clean by the sewage 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, and is diluted again, and then the sewage suction is completed.
(4) Pipeline dredging and sewage interception
Set a plug to block the well chamber inlet pipeline of the first working section from top to bottom, and then block the downstream inspection well outlet and other pipeline openings, leaving only the inlet and outlet of this section of pipeline.
(5) high-pressure cleaning vehicle dredge
Use a high-pressure cleaning vehicle to dredge the pipeline, the hose of the high-pressure cleaning vehicle extends into the lower part of the upstream inspection well, the water gun is aimed at the pipeline to spray water in the direction of flowing water, and the downstream inspection well of the sewage pipeline continuously sucks indoor sludge.
(6) Pipe dredging and ventilation
Before the construction personnel 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. Construction personnel must wear safety belts, gas masks and oxygen cylinders when entering the well.
(7) Dredging
Before entering the well, organize the construction personnel to take safety measures, and manually sort out the remaining bricks, stones, some sludge and other residues in the inspection well until the sorting is completed.
Then according to the above explanation, the downstream sewage inspection wells are dredged one by one, and the inspection wells mainly arranged in the upstream are blocked during the construction dredging time to prevent the upstream sludge from flowing into the pipeline or into the upstream inspection wells and pipelines when the pipeline is full of water during the downstream construction time.
Construction Scheme of Dredging Project (II)
I. Basis for compilation
1, the task of * * annual special environmental improvement project issued by Chengdu City Appearance and Environment Bureau.
2. The silt dredging task book issued by Chengdu Water Conservancy Bureau.
3. Relevant technologies and safety operation specifications
4. Time limit: from mid-May to the end of May.
Second, the project overview:
This project is a part of river dredging construction of * * urban environment special improvement project. In order to ensure the expected effect of the regulation project, the riverbed is dredged to meet the design requirements of riverbed elevation, flood control and navigation, and a clean and tidy river is also built. This demolition is a professional dredging of the river section.
This project is a dredging project of Daodi River, with a total length of 5700 meters from the second ring road to the third ring road of Daodi River. The average width of the bottom river in this section is10.0m, and the river bank is a vertical dike with a height of H = 3.5M. The average width and depth of river silt are 5.0M and 0.8M respectively.
Three links, one leveling and temporary facilities
Water: use the water source of management facilities along the river to solve drinking water.
Electricity consumption: electricity consumption for lighting and drainage (or power supply by street lamps on river banks) is used by the nearby units for construction at night.
Road: Use the channels on both sides of the river to organize transportation 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: Due to the short construction period of this project and the long length along the construction site, our company considers not to build temporary facilities on the construction site. But to rent houses nearby, not temporary facilities.
Fourth, personnel organization.
In order 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 Conservancy Bureau. To this end, our company has set up a dredging engineering headquarters headed by Yu Xianglin, the company manager, Zhou Jinhua, the deputy manager in charge of logistics, and Yuan, the manager of the mechanical department in charge of mechanical equipment, as the deputy leader, to be responsible for the implementation of the project.
Verb (abbreviation of verb) construction measures
1. construction section division: due to the long distance along the river, according to the requirements of dredging volume and construction period, dredging can be carried out in 3~4 sections, with one river crossing each section. All the excavated earthwork should be sent abroad.
2, construction measures:
① Drainage:
Dig a longitudinal drainage ditch outside the river silt to make the water flow back into the tank. Earthwork piles form ridges on the edge of the trough, so that a small amount of river water can be discharged 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 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, and the traffic of earthwork vehicles is inconvenient, so 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 is dredged manually and transported ashore, and then the earthwork is cleaned and dredged by dredgers, loaders and cars. 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.
At the top of some dikes of this river, there is a green belt slope. Only at the top of the slope, transport machinery and excavation machinery can go down the river to dredge silt. Therefore, the river silt in this section can only be dredged manually, then transported manually to the top of the green belt slope, and finally transported out by transportation machinery. Therefore, the dredging unit material price of this part of silt is higher than the direct mechanical excavation freight. According to our calculation, this part of the engineering quantity accounts for 40% of the total engineering quantity. In other river sections, we consider using excavating machinery to directly open the dredged silt in the river, but there is no downstream lane in the whole section of Diandi River, so we consider using silicon bricks to lay temporary downstream lanes at appropriate positions of Diandi River. According to the site conditions, there are three locations on Xiahe Horse Road. After the silt in the river bed is removed, the silicon blocks will be removed manually and go down the river.
Intransitive verb garbage dump
In order to cooperate with the smooth removal of dredged riverbed silt, our company will contact the dumping site near the Third Ring Road. The dumping area is about 6 ~ 8 kilometers away from the dredging area. After the transport vehicles enter the traffic road, the road traffic is smooth. Equipped with bulldozers to level the fields, which is convenient for bulldozing.
Seven, cleaning and cleaning
According to the relevant regulations of dust control in Chengdu, in order to ensure that the river dredging does not affect the surrounding environment, the cleaning work should be done well during the dredging process, and the person in charge should be responsible for it. Each construction section is equipped with 20 migrant workers respectively. Responsible for protecting the facilities formed along the river and laying straw mats at the exit; Be on duty at intersections and organize traffic. Every earth-moving vehicle can only be released after cleaning the wheels and carriages, so as to ensure that the people have a clean and comfortable environment every day.
Eight, safety measures
Set up guardrails and warning signs at the main traffic exits, assign special personnel to be on duty, and organize traffic at intersections. Do a good job of 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 prohibit drunk driving.
Nine, mechanical equipment
Two crawler excavators ex200.
2 ZL50 loaders
30 5T dump trucks
X. Staffing
General worker 20 people
Construction Scheme of Dredging Project (III)
I. Overview:
The XX River was cleaned up when it was undecided, and now it is seriously rancid and blocked. Therefore, Yin Haohe was entrusted to dredge the river and conduct on-site inspection. The proposed dredging length is about 2000 meters.
Duration: 12 days: 1 day preparation. It is planned to dredge 200m every day, level the river bottom and dismantle the cofferdam 1 day.
Second, the program:
Find out the inflow of water from the upper reaches of the river in normal times, the specific location and direction of infrastructure such as bridges and pipelines along the way, and the depth of river sediment deposition. According to the requirements of dredging workload and construction period, organize manpower and machinery, and prepare materials in consideration of flood control and flood season requirements.
1, organization:
The river course rerouting 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 dredge in groups and sections. In the process of dredging, it is necessary to maintain the normal water supply of the old Weihe River, with half dredging and half running water; Dredge the southern half of the river first, and then dredge the northern half.
2. Cofferdam:
A 500-mm-thick brick cofferdam is set in the lower reaches of the river, which is flush with the top surface of abutment foundation and can be used as a cofferdam when the realignment project is connected with the old river (the gate is 3m wide and has a 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 Fishery Association and downstream of Tangzhuang Bridge respectively, and the height should be 0.7m higher than 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 cofferdam construction is completed, the accumulated water in the river channel is discharged to the downstream river channel of the cofferdam by using the sewage pump, and a longitudinal water collecting ditch is excavated along the bottom edge of the old river channel to collect the accumulated water in the river channel before the downstream cofferdam. Dig 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, dredge:
Take three excavators as a group and combine them into a trapezoidal queue. An excavator at the bottom of the river is in front, cleaning the sediment at the bottom of the river to the south while digging, and placing the sediment above the slope as much as possible, and at the same time excavating a catchment ditch with a depth of about 50cm at the bottom line on the south side of the river; The second one is above the slope, and the silt dug by the first excavator and the turf roots on the slope are cleaned to the beach on the Henan side. The third one is on the last side, and the silt dug by the second excavator is collected.
The dredging in the southern half is completed, and the sediment in the northern river channel is cleaned in the same way. At this time, the accumulated water has been concentrated in the southern half of the river, and there is no need to dig a longitudinal catchment ditch at the bottom line of the North River. After dredging, the river bottom will be filled up.
Step 5 clean up:
The sludge in the beach is dried and dehydrated and transported to the owner by a well-sealed transport vehicle.
6, cofferdam demolition:
The cofferdam is reserved with movable gates, which can meet the normal water flow. After the Weihe River regulation project is completed and the old rivers are connected in turn, they will be demolished to restore the smooth flow of the rivers. After the upstream dredging of cofferdam is completed, the downstream cofferdam can be removed and the river channel can be restored.
7. Flood control:
When receiving the flood warning information, immediately stop dredging, mobilize for flood control, start the emergency plan, and prepare for flood control. After obtaining the exact information, all construction machinery will be evacuated from the river within 30 minutes, and the downstream cofferdam will be dredged to ensure the smooth flow of the river.
Third, matters needing attention:
1, cooperate with the owner to complete relevant procedures before dredging;
2, along the dredging face range (such as slope, floodplain) of some crops, coordinated eradication in advance;
3. When silt is temporarily piled up on the beach, the site should be cleared in time to realize the temporary road for transporting vehicles;
4. The dredging under roads and bridges needs to protect or protect the original traffic facilities;
5. Investigate the distribution trend, buried depth and specific location of pipelines (such as national defense optical cables, electric power, communication, water supply and gas pipelines, etc.) in the dredged river section, make records, and make obvious signs on the spot;
6. Leak-proof measures shall be taken during sludge transportation, and vehicles shall leave the site for clearing to prevent road pollution;
7, strengthen the protection of green vegetation on both sides of the river, not malicious destruction of trees on both sides of the river;
8. The isolation fence is dredged and restored to its original state.
Four, personnel machinery:
1. Personnel arrangement: 4 managers, 6 skilled workers, 6 general workers 16 and 40 mechanical operators.
2. Main machinery: 6 excavators, 12 dump trucks, 2 loaders and 2 bulldozers.
3.6 sewage pumps and 4 submersible pumps.