River dredging generally refers to river regulation and belongs to water conservancy projects. Through mechanical equipment, the silt deposited at the bottom of the river is blown and stirred into turbid water, which flows away with the river and plays a dredging role. Below I will share with you the technical methods of river dredging construction, and welcome you to read and browse.

1, preparation before dredging

Before river dredging and excavation, the vegetation, construction waste and other sundries within the scope of river excavation should be cleaned up first. The cleaning work plan is carried out by manpower and excavators. Surface vegetation, such as cotton stalks and reeds, shall be manually pulled out. Construction waste, reed roots, tree roots, etc. Dig with an excavator to pile up or bury outside the site designated by the owner, and the removed plant roots will be burned in the place designated by the owner. The scope of foundation cleaning shall be 2m beyond the scope of excavation or soil piling.

2, mud pump mud flushing construction and transportation

(1) Water diversion and drainage

The flushing mud required by the mud pump for earthwork excavation can use the nearby river water. There is a diggable drainage ditch along the river bank in the dump area, with a depth of 0.8m- 1.0m and a bottom width of 0.5m-1.0m. The waste water in the sludge discharge area will be discharged and introduced into the sludge flushing area for reuse.

(2) According to the construction section, high-pressure water pump and mud pump are installed on the mud flushing surface, rubber nylon pipes for mud discharge are laid, and submersible pumps are installed in Dadonghe River to extract clean water for high-pressure pump water, and the backwater after mud pumping can be used.

(3) Start the high-pressure pump to wash the ground mud with a water gun to form a pool, put down the mud pump to suck out the mud, input it into a special mud truck, and then transport it to the designated place. In case of rivers with inconvenient traffic, directly input the mud into the designated mud pit.

(4) When flushing with mud pump, leave 0.3m protective layer at the river bottom and river slope. After the river scouring and excavation, manually repair the river bottom and river slope to make the excavation outline accurate and the bottom slope smooth.

(5) Matters needing attention in hydraulic excavation construction and excavation quality control:

A, overall arrangement of construction, scheduling good washing and dredging warehouse work in turn, improve the utilization rate of equipment;

B, mud pipe should be smooth, avoid dead bending;

C, the mud outlet should be out of the truck for a certain distance, and should be 50 cm higher than the mud discharge surface;

D, mud pipe joint fastening tightly, the whole pipeline and joint shall not leak oil, often check whether the mud truck leak slurry, once found, should be timely repair or replacement;

E, mud pipe bracket must be strong, layout as far as possible to avoid damage to other facilities;

F, strengthen the patrol inspection of mud conveying pipeline, pay attention to the excavation according to lofting piles, master the working condition of the pipeline, and prevent the river from overbreak, dike collapse and mud overflow.

3. Case protection project

The "sub-projects" of the case protection project can be summarized as: small wooden pile project, sheet pile project and slope improvement project.

3. 1 piling works

(1) concrete pile fabrication

Fabrication of concrete piles: precast by qualified manufacturers in strict accordance with the requirements of design drawings, and transported to the site that reaches the designed strength.

(2) Pile driving scheme

I. Selection of piling machinery:

B, when piling, positioning should be carried out first, and the elevation of pile top should be measured, and then the control line should be carried out.

C, in order to prevent pile deviation during pile pressing, a temporary operating platform shall be built on the shore to facilitate pile fixing, pile digging, retaining wall construction, coping and other processes.

D, artificial piling.

3.2 Plug-in sheet pile construction

There are two forms of sheet pile: one is A 1 sheet pile, and the other is A2 sheet pile.

(1)A 1 Inserted pile technology: drive concrete pile, install retaining plate in the pile, lay non-woven geotextile at the joint of retaining plate and soil, drive the pile to the design elevation, chisel off the top of the pile by 25cm, and pour the longitudinal reinforcement of the pile, the exposed reinforcement of retaining plate and geotextile into the concrete of the pile cap (the concrete label of the pile cap is C25).

(2)A2-type pile insertion program: The specific operation is based on A 1 type pile insertion program, and the guide beam with a cross section of 400mm*300mm and the coupling beam with a cross section of 300mm*300mm are used to pull out the pile at the estuary 2m.

(3) Installation of retaining plate: the retaining plate is installed inside the concrete pile. Because there is a certain distance outside the shore, after the retaining wall and capping construction are completed, backfill soil on the inner side of the concrete pile is compacted, and then the retaining plate is installed. When installing the retaining plate, the plate and the pile are temporarily connected and fixed with iron wire, and then backfilled on the road surface, and the road surface is compacted mechanically or manually.

(4) Geotextile: According to the design requirements, geotextile is laid on the board on the water retaining side.

4. River slope greening

In the greening project of river slope, seedling varieties should be selected according to the actual situation on site.

Green space layout is a necessary work before seedling planting. The main work of green space layout is:

(1) Site cleaning

Remove all garbage, soil layers and weeds unsuitable for planting in the site, bury them deeply, and pile stones for other purposes.

(2) Terrain adjustment

The terrain belongs to the whole green space? Body? The terrain is related to the appearance of the whole green space and the smoothness of the forest edge line, which is the foundation of the whole green space. Therefore, terrain adjustment is an essential work link.

Construction procedures should be arranged reasonably during construction to avoid rework. The vertical design should be adjusted in strict accordance with the requirements of the drawings to ensure the adjusted terrain quality. The terrain after construction should be full, natural, smooth and accurate, and meet the design requirements. The setting-out elevation should be higher than the design elevation (the throwing height depends on the soil conditions at the site, and the final settlement height should reach the design elevation), so as to ensure that the design requirements can be met after the rain or after sprinkling water.

(3) Site leveling

The method can be implemented manually, and the topsoil is excavated and sorted with hoes or rakes, so that large clods of soil are broken and leveled, weeds and stone particles are removed, soil water permeability is improved, hardening is prevented, and plant root system growth is facilitated.

;