Earthwork excavation construction scheme

(1) Investigate the site and remove the ground and ground obstacles.

(2) Protect the survey datum pile to ensure the accuracy of the elevation position and size of earthwork excavation.

(3) Prepare to excavate construction facilities such as machinery, personnel, electricity, water and roads.

Step 2 clear the table

All surface weeds, stones, sundries, humus, tree roots, etc. within the scope of the project shall be cleaned, leveled and compacted, and the cleaning thickness shall not be less than 0.3m The removed waste residue shall not be discarded anywhere, and transported to the waste yard by dump trucks.

3 Earthwork excavation

The earthwork excavation mentioned here mainly refers to the earthwork excavation within the scope specified by the tenderer, and the excavated earthwork shall be transported to the place specified by the tenderer, and the pile height shall not exceed 1985 Yellow Sea elevation12.20m.. ..

(1) construction preparation

① Preparation of construction materials: Earthwork excavation is affected by weather, geological conditions and original buildings, and the following work should be done before excavation:

Review and analyze the construction drawings and formulate the construction plan.

Understand the local hydrological and meteorological conditions.

Understand the geological conditions of the construction site.

D. Burying of buildings and pipelines within the construction scope.

Draw the plan and cross section of earthwork excavation.

(2) Measurement and lofting

Using the temporary control points laid out, the excavation edge and excavation depth are determined by lofting. When laying out the excavation sideline, 30~50cm should be added to the design sideline and marked. The excavation size of foundation pit bottom should not only meet the requirements of building outline, but also consider the requirements of drainage facilities and formwork installation.

(3) Earthwork excavation requirements

① Construction preparation

A before earthwork excavation, the underground and ground obstacles in the construction area shall be cleaned and treated according to the requirements of the construction plan.

B the dimensions of the positioning control line (pile), standard horizontal pile and slotted grey line at the location or site of the building or structure must be inspected; And complete the pre-inspection procedure.

C, construction at night, should have enough lighting facilities; Dangerous areas should be clearly marked, and the excavation sequence should be arranged reasonably to prevent wrong excavation or overbreak.

D measures should be taken to reduce the underground water level according to the local engineering geological data when excavating foundation pits and pipe trenches with underground water level. Generally, it should be lowered to 0.5m below the excavation face before excavation.

E roads, bridges and unloading facilities that construction machinery passes through when it comes into the site should be inspected in advance, and preparations should be made for reinforcement or widening when necessary.

F, the selection of earth-moving machinery should be based on the terrain and working conditions of the construction area, the type and thickness of soil, the total project amount and the construction period, and make full use of the efficiency of construction machinery to determine and prepare the construction plan.

G. The layout of running routes in the construction area shall be determined according to the size, mechanical properties, transportation distance and topography of the works in the operation area.

H. Trim the slope gradient and clean the bottom of the groove at the position where the mechanical construction can't work. , should be equipped with manual work.

1. Machines and tools: Earthmoving machinery includes excavators, bulldozers, shovels (both pointed and flat-headed), trolleys, small white wires or 20 # lead wires, steel tape measures and slope scale.

J, familiar with drawings, technical disclosure.

② Operation technology

Process flow:

Determine the excavation sequence and slope → average excavation by sections and layers → trimming and bottom cleaning.

B. determination of slope:

The slope excavated in this project meets the design requirements. If it is still unstable during construction, contact the design to change the excavation plan.

Mechanical excavation

Excavation should reasonably determine the excavation sequence, route and excavation depth. In this project, the excavator is used to cooperate with the earth stacker for excavation, and the earthwork excavation should be carried out in layers and sections from top to bottom. Make a certain slope at any time to facilitate drainage. In the process of excavation, the state of the slope should be checked at any time. When excavating the foundation pit, it is forbidden to dig below the design elevation. If the design basement elevation cannot be accurately dug, a layer of soil can be left above the design elevation without digging, and it can be dug manually after leveling. When excavating with backhoe, it is advisable to use about 50cm for temporary soil excavator.

Manual repair and excavation

Earthwork that cannot be excavated by mechanical construction should be excavated manually at any time, and the soil should be transported to the place where it is excavated by machinery with trolleys, so that it can be excavated by machinery in time. When repairing and cleaning the bottom, copy out the horizontal line at the groove edge 50cm away from the design elevation at the bottom, nail it with Xiao Mu lips, and then dig the temporary soil layer manually. The pile head of cement mixing pile shall be excavated along the pile without damage to the basement elevation, and the cement mixing pile shall be cut according to the cut-off elevation requirements, and the pile top shall be leveled. At the same time, use the axis (center line) to guide the pile to pull through the line (with small wire or lead wire), check the size from the groove edge, and determine the groove width standard, so as to trim the groove edge. Finally, clear the earthwork at the bottom of the trough.

(3) Construction in rainy and winter

An earthwork excavation should not be carried out in rainy season, otherwise the working face should not be too large and should be completed by stages.

B. When excavating earthwork in the rain period, attention should be paid to the stability of the slope. When necessary, the slope gradient can be appropriately slowed down or supported. At the same time, an earth embankment or ditch should be built around the outside of the pit to prevent the inflow of surface water. Check the slope, support and earth embankment frequently, and handle the problems in time when found.

C earthwork excavation should not be carried out in winter. If construction must be carried out in winter, the construction method should be carried out according to the winter construction plan.

D. When earthwork is excavated by anti-freezing method, the topsoil can be covered with thermal insulation materials or raked before freezing, and the ploughing depth should be determined according to local temperature conditions. Generally not less than 30cm. When excavating a foundation pit, the foundation soil under the foundation must be prevented from freezing. Loose soil with appropriate thickness shall be reserved above the elevation of the basement. Or covered with other thermal insulation materials. When the foundation and foundation of adjacent buildings or structures are exposed due to earthwork excavation, anti-freezing measures should be taken to prevent freezing injury.

④ Quality and safety control measures

A, according to the requirements of drawings carefully lofting, earthwork excavation slope should comply with the design requirements, to avoid collapse caused by excessive slope. In order to ensure the quality of the slope, backhoe should be excavated close to the slope line to ensure the smoothness of the slope and try to avoid under-excavation and over-excavation.

B. After the excavation is cleaned, the pile number, coordinates and elevation shall be restored in time, and eye-catching signs shall be made.

C, in rainy days, intercepting ditch should be set at the top of the excavation slope, drainage ditch and collecting well should be set in the excavation area, and drainage work should be done in time to prevent water accumulation in the foundation pit.

D, in the process of excavation, we should always keep the designed slope line for step-by-step excavation, to avoid landslides caused by steep temporary slopes during excavation, and at the same time strengthen the observation of slope stability.

E, it is forbidden to pile up heavy objects at the top of the excavation slope to avoid collapse.

(2) earthwork sinotrans

The earthwork of this project is transported by 5t dump truck, transported to the place designated by the Tenderee, and stacked according to the requirements of the Tenderee. During the construction period, the spoil ground shall be managed, and it is forbidden to transport earthwork outside this project to the spoil ground of this project. Roads involving engineering transportation pollution shall be cleaned up in time according to the requirements of the road administration department.