How does on-site supervision confirm the amount of earthwork excavation?
When we do the amount of earthwork excavation, we calculate it based on the construction drawings. Each site situation is different, but there are several basic formulas that can be provided to you: (1). Earth excavation amount = foundation pit length * width * depth depth * slope ratio * depth. (2). Reserved soil = amount of excavated earthwork - amount of foundation concrete earthwork (3). Amount of externally transported earthwork = amount of concrete. Calculate the approximate imaginary square of the earth based on these formulas, and then convert it to the actual situation. The formula for the amount of earthwork excavation for independent foundations
The formula for calculating the amount of earthwork for foundation excavation is V=1/3* (s up, s down, square root down, s up*s down)
Concrete The calculation formula for an independent foundation is V=length*width*height
You cannot use the same formula for earth excavation
The upper and lower sections of an independent foundation are of different sizes and are of the same height. The independent foundation bar of formula or unequal height can be: length*width*height (bottom) length*width*height (middle) length*width*height (top)
Ordinary independence of slope section Foundation
Length*width*height (a*a b*b a*b)*h/3 Is the amount of earthwork excavation calculated according to the design shape correct?
Of course it is not wrong, you go check it out Just check the geotechnical specifications and you will know whether you need to write the supervision side station for earth excavation every day
The scope of side station supervision: "Law for the Supervision and Management of Side Stations during the Construction of Housing Construction Projects (Trial)" Housing construction stipulated in this law The key parts and processes of the project, in terms of basic engineering, include: earthwork backfilling, concrete pouring pile pouring, underground diaphragm walls, soil nail walls, post-pouring belts and other structural concrete, waterproof concrete pouring, and detailed structural processing of membrane waterproofing layers. Steel structure installation; in terms of main structure engineering, it includes: concealment process of beam and column node steel bars, concrete pouring, prestressed tensioning, prefabricated structure installation, steel structure installation, grid structure installation, and cable membrane installation. Sample article: Construction conditions: Commercial concrete is used, the strength grade is C30, the production serial number is HO30910250003, and a car pump is used on site. Supervision conditions: The concrete slump is checked 4 times, and the actual slump is 150mm, which meets the requirements of the concrete mix ratio. Make 2 sets of concrete test blocks (No. 052, 053, of which the test block No. 053 is the witness test block). The concrete pouring process complies with the requirements of the construction acceptance specifications. Problems were found: 1. The lower corners of the beams were not vibrated in place and the vibrating time was not enough; 2. The gluten of the board was stepped down, which reduced the bending strength of the board. Treatment opinions: 1. The vibrator rod is required to be inserted in place, and the vibration time is appropriate when the gap in the formwork of this part is just exposed; 2. The construction worker is required to go to the site to guide the pouring, build the working bridge, add steel brackets, and arrange the steel bars in time. Submit a supervision notice, and the recipient shall be the construction unit** What should the supervision do after earth excavation?
Supervision after earth excavation should:
1\After confirming the excavation of the foundation pit *** size and elevation of the foundation pit, and make a preliminary determination of the base soil quality. If any discrepancy with the geological survey is encountered during excavation, it should be reported to the construction unit in time and contact the geological survey design for technical confirmation
2\Observe whether there is instability in the foundation pit and whether the existing foundation pit support meets safety requirements.
3\Organize the project construction unit to conduct horizontal displacement detection of the foundation pit regularly or irregularly
4\ Carry out precipitation inspections and confirm precipitation shifts.
What are the key points for earth excavation supervision and control?
Supervision should pay attention to the following:
4.1 Review the construction plan for foundation pit excavation based on the geological survey report, as-built drawings of underground pipeline structures, foundation design drawings and deep foundation pit support design drawings, as well as the "Code for Construction and Acceptance of Earthwork and Blasting Engineering" (GBJ210-83), In particular, deep foundation pits must be carefully reviewed and the "Construction Organization Design Review Form" (A2) must be filled out.
4.2 Based on the measurement control points (plane control piles and level points) and planning red lines in the general plan, review and recheck the opening lines placed by the construction unit to ensure accuracy. And fill out the "Project Inspection Application Form" (A4).
4.3 Before excavation of a deep foundation pit, a professional team must monitor the foundation pit supporting structure and surrounding environment (road pavement, residential buildings, etc.). Conduct regular displacement and settlement observations and report the results to the supervision unit.
4.4 Before excavation of a deep foundation pit, the quality of the supporting structure must be tested. Excavation is allowed only after passing the test.
4.5 Check whether the performance of the earth excavation machinery is suitable for this project and whether the operator is certified.
4.6 If blasting technology is used for excavation, the construction party and owner should be urged to report to the *** competent authority, review whether the blasting plan is reasonable, and fill in the A4 form.
4.7 During the excavation process of the foundation pit (trough), frequently inspect the construction site and pay attention to the following issues:
4.7.1 Whether there is any displacement of the axis piles, gantry plates or horizontal piles; Whether the slope of the pit meets the design requirements;
4.7.2 The height, location and scope of the soil piled beside the pit, and the height of the stacking of building materials meet the requirements;
4.7.3 Earth walls, pits Bottom seepage;
4.7.4 Surface water and rainwater scouring the slope, and whether the drainage ditches around the slope are working normally;
4.7.5 Are there any cracks in the surrounding ground?
4.7.6 Whether there is any local landslide;
4.7.7 Abnormal soil quality, local soft soil, ancient tombs, ancient wells, and local obstacles;
4.7.8 Construction safety (Such as excavation of lower floors, operations under excavators, etc.);
4.7.9 Guardrails or obvious signs should be set up around foundation pit excavation to prevent people and vehicles from falling into the foundation pit, and red lights should be set up at night. Warning;
4.7.10 Do a good job in excavation project measurement and record soil types and boundary conditions (elevation, range).
4.8 Protection of buildings and foundation pits in foundation pits
4.8.1 For projects where piles are driven (or drilled or dug) first and then the foundation pit is excavated, the The protection measures for engineering piles must be clearly defined in the construction plan, and professionals must be arranged to monitor the displacement, inclination and pile integrity of the engineering piles during excavation.
4.8.2 For deep foundation pits that may be exposed for a long time, the design unit should evaluate the weathering speed of the foundation rock (soil) layer, the possibility of pit collapse or the base will bulge, and take corresponding protection Measures (such as shotcrete, laying protective layer, etc.).
4.9 Trench Inspection
After the excavation of the foundation pit (trough) is completed and cleaned, before foundation construction, organize the relevant units to inspect the trench. After the trench inspection, , confirm the qualification, the relevant person in charge signs to confirm, and fill in the project inspection application form (A4). The content of the trench inspection is as follows:
4.9.1 Whether the dimensions (length, width, depth) and slope of the foundation pit are consistent with the design drawings. The quality standards are shown in the attached table;
4.9.2 Foundation The soil layers on the pit wall are layered, especially whether the base soil layer is consistent with the geological report and design drawings, whether there is underground water exposure, and whether drainage measures need to be added;
4.9.3 Important parts of the superstructure (i.e., stress-bearing Whether the soil quality (larger or settlement-sensitive parts) meets the design requirements (for raft foundations);
4.9.4 Foundation treatment (or only local) effect inspection;
4.9 .5 Pile head treatment;
4.9.6 What is the underground water seepage situation at the foundation pit and bottom, and whether the drainage facilities are working normally. Earth excavation on site! How to command the excavator to dig soil? I only know how deep to dig
I need to use a level to control the elevation at any time, not to over-excavate, and to control the edges of the foundation pit. Is it necessary to keep records at the side of the earth excavation supervision station?
There are elevations before and after excavation, so it can’t be considered a large-scale operation. You are really talented. It was also the first time I was drunk and had to stand aside during excavation work. There was no one at the construction unit, and the supervisor was required to be present at all times.
The owner treats the supervisor as his younger brother. What information does the supervisor require from the earth excavation unit?
Enterprise qualifications, business license, production safety license, earth excavation plan, earth excavation information, etc. How to get the supervisor to confirm the information when rushing to work on site
The first thing to emphasize is: no matter how tight the construction schedule is, those who should follow the process must follow the process. Projects often come with certain risks. Don't be afraid of ten thousand, just be afraid of the worst. . How should the responsibilities be divided at this time? How to be responsible? This is a very controversial issue. In order to avoid these accidents, it must be confirmed by the supervisory unit.
The staff of the supervision company are responsible for the following work responsibilities and must respect the work responsibilities of the third party:
1. Confirm the quantity of the project: Since it is included in the bill of quantities when signing the contract The listed quantity of work is an estimated quantity, and the actual construction may be different from it. Therefore, when the construction unit pays the project progress payment, the actual quantity of work completed by the contractor shall be confirmed or verified, and the payment shall be based on the quantity of permanent work actually completed by the contractor. Within 7 days after receiving the report from the contracting unit, the supervision unit will follow the design drawings and completed project quantities, and notify the contracting unit to participate 24 hours before the actual measurement on site. The contracting unit provides convenient conditions for measurement and sends personnel to participate.
2. Strict quality control: The project supervision franchise unit will inspect the contractor's project quality according to the quality standards agreed in the contract. If it meets or exceeds the agreed standards, it will be given quality recognition; if it fails to meet the requirements, it will be Get together with the company and ask the contractor to repair it. The contractor shall rework according to the requirements of the construction engineer until it meets the agreed standards. If the contract fails to meet the agreed standards due to the contractor's reasons, the contractor will bear the renovation costs and the construction period will not be extended. If the construction unit fails to meet the standard due to reasons, the construction unit shall bear the additional contract price for rework, and the construction period shall be postponed. If the standards are not met due to reasons between both parties, the responsibilities shall be borne by both parties respectively.
The quality of the project constructed by the contractor should meet the standards agreed in the contract.
3. Control the progress of the construction period: After the project starts, the contract performance will enter the construction stage until the project is completed. The main task of the supervision engineer in progress management at this stage is to control the execution of the construction work according to the schedule and ensure that the construction tasks are completed within the specified contract period. If the actual progress lags behind the planned progress due to reasons caused by the contractor, all consequences shall be borne by the contractor. The unit is responsible for this. Regardless of whether the actual progress is ahead of schedule or behind the planned schedule, as long as it is inconsistent with the planned schedule, the supervision engineer has the right to notify the contractor to modify the schedule plan in order to better coordinate and manage the subsequent construction.
The above are just personal suggestions. It is best to do everything according to the process!