Open ditch drainage construction scheme
catalogue
I. Overview of the Project
Second, the geological survey
Third, the precipitation scheme selection
Fourth, well point design
Five, the main construction equipment
Sixth, the labor force plan
Seven, the main construction methods
Eight, measures to ensure the quality of the project
Nine, the construction progress plan
X. Safety measures
I. Overview of the Project
The proposed Jiangnan Fengjing is located in the northwest of the intersection of Renmin West Road and Tianjin North Road in Shuyang County. Raft foundation is used as the foundation form, and three layers of clay are used as the bearing layer.
Second, the geological survey
1. The groundwater types of the site are upper pore phreatic water and lower micro confined water. The groundwater level is about 1.6m below the natural ground, the perennial high water level is about 0.8m below the natural ground, the low water level is about 2.00m below the natural ground, and the buried depth of the lower micro confined water is 4.2m The groundwater recharge is mainly atmospheric precipitation and surface seepage.
2. See the Geotechnical Investigation Report of Jiangnan Fengjing of Shuyang Jinli Real Estate Co., Ltd. for the geotechnical conditions of the site.
Third, the precipitation scheme selection
The commonly used methods to artificially reduce groundwater are light well point, jet well point, electro-osmosis well point and tube well point. The selection of precipitation scheme should be determined after comprehensive comparison and analysis of various methods according to soil layer properties, permeability coefficient and engineering characteristics.
Electroosmosis well points are mainly used for silt and muddy clay; The depth of precipitation at the injection well point is large, but the cost is high;
The installation of light well point equipment is simple and fast, which is a common method in dewatering construction at present, but the dewatering radius is small; The well point dewatering depth of tube well is large, and the influence radius is large, so it is often comprehensively utilized with other methods.
The excavation depth of the foundation pit is about 5.2 m and the width is about 60 m. In order to achieve good dewatering effect and make the foundation pit meet the requirements of earthwork excavation as soon as possible, referring to the previous dewatering experience in this area, it is decided to adopt the dewatering scheme combining tube well dewatering with open ditch drainage, which is safe, reliable, economical and reasonable.
Four, well point design basis
1, according to
(1) foundation drawings of Jiangnan Fengjing basement and clubhouse
(2) Engineering characteristics and geotechnical investigation report.
(3) Technical Code for Building and Municipal Dewatering Engineering (JJ/ 1 1 1-98)
2. Well point design
48 tube wells are evenly arranged around the foundation pit, and 8 tube wells are arranged in 9# and 10#, with a depth of 10m and an opening of 600 mm. The filter tubes are made of 300mm sand-free concrete with an outer diameter of 400 mm. The positioning of tube wells should avoid the foundation.
3. Pavement drainage
Around the foundation pit, a circle of drainage ditch is arranged 2 meters away from the foundation pit. The drainage ditch is 40 cm deep and 30 cm wide, and an 800ⅹ800ⅹ800 mm collecting well is left on the drainage ditch every 40 meters .. At the bottom of the drainage ditch, the slope is 0.5% ~ 65438 0% to the collecting well. The drainage ditch is plastered with brick cement mortar. The groundwater pumped by the tube well is directly discharged into the drainage ditch and discharged from the site at the place designated by Party A. ..
Five, the main construction equipment
Name, specification, model and quantity
1 drilling rig
Submersible pump 1.5 inch ~ 2.5 inch 66 sets (10 set for standby)
500m3 of rice stone and gravel.
Intransitive verb labor force plan
The builder is 1.
1 quality inspector
Safety officer 1
Surveyor 1
Documentary 1 person
Mechanical electrician 1 person
Well point installer 1 person
Seven, the main construction methods
1. Equipment mobilization-well point positioning-tube well construction-trial pumping-dewatering-foundation pit excavation-foundation construction-waterproof layer construction-foundation pit backfilling-main body construction to settlement joint construction-tube well closure-equipment exit.
2, the construction method
(1) tube well positioning: according to the axis control point, use theodolite to position, and its position should avoid foundation beam, column and wall.
(2) Hole-forming: After the drilling rig is in place, it should be stable to ensure that it will not move obliquely in the construction project, and the porosity should be less than 65438 0%.
(3) Installation of tube well: The tube well adopts sand-free concrete filter tube, and effective measures should be taken to make it tight and firm to prevent tube well from dislocation and mud leakage. After the well pipe installation is completed, fill the hole with 1000 mm thick rice stone filter material. The gap between the upper shaft wall and the soil wall is filled with stones of 1-3. 15 cm.
(4) Well washing: After the tube well is installed, pump water to wash the well immediately to prevent the filter tube from being blocked due to idle time.
(5) Pumping: Clean water is left after well washing 12-24h, and pumping can be continued at this time. If it is turbid and has a high silt content, it is necessary to find the reason.
(6) Well tube sealing
After no further dehydration is needed, close the well tube. When closed, the well pipe 2m below the cushion shall be filled with C20 concrete. In order to strengthen the waterproof effect of construction joints, the side wall of the bottom plate is treated with double-channel water stop. If Party A has other uses, after the well pipe is no longer used, it shall send people to do a good job of protection.
Eight, organizational guarantee measures
1, organizational guarantee measures
Establish post responsibility system and quality supervision system, clarify the division of responsibilities, implement the responsibility of construction quality control system, and perform their duties.
2, technical guarantee measures
(1) All raw materials are supplied by our qualified suppliers. Do a good job of re-inspection after the materials enter the site, and they can only be used if they are qualified.
(2) The quality of the installation well point is the prerequisite for the dewatering effect to meet the design requirements. The company sends experienced construction personnel and quality inspectors to strictly control the quality, especially the key links, such as diameter molding and filter material input.
(3) Send a builder with a strong sense of responsibility to check the equipment operation. No slack is allowed. If problems are found, timely repair or replace spare equipment to ensure the quality of precipitation.
(4) Work closely with all construction teams to ensure the normal operation of dewatering equipment.
(5) In order to ensure the effect and quality of precipitation, it is necessary to provide the retention force of 125KVA to prevent the water level from rebounding after power failure. Repeated fluctuation of water level not only affects the construction period, but also endangers the foundation pit.
The security of the perimeter.
3 Economic guarantee measures
Establish a reward and punishment system. Reward those with excellent construction quality, and encourage them to always put quality first in their work, make persistent efforts, and make the project quality better. Those with poor construction quality will be punished, and those with serious construction quality will be removed from the list.
4. Strengthen safety monitoring. Set up water level observation wells and settlement observation points, and use observation data to guide and control precipitation to ensure the safety of the surrounding environment.
All construction units should cooperate closely to speed up the construction progress, shorten the precipitation period as much as possible, and avoid the impact of long-term precipitation on the environment.
Nine, the construction progress plan
1, equipment in 1 day.
2. The positioning of tube well is 1 day.
3. Tube well construction 10 days.
4. Equipment installation 1 day
5. 1 day equipment debugging, trial pumping and well cleaning.
6, precipitation began (can be dug after 7 days) is expected to be 90 days.
7. Dismantle the equipment for 2 days
8. Equipment withdrawal 1 day
X. Safety measures
1. During drilling construction, a mud pit shall be set beside the drilling rig, and personnel shall be sent to clean it in time.
2. During drilling construction, there should be a special person on duty beside the drilling rig to prevent accidents.
3. In the process of precipitation, there should be someone on duty. If the amount of water in the well is small, prevent accidents caused by dry pumping of submersible pump.
4. When drilling and dewatering stop construction, turn off the power supply.
5. In the process of drilling construction, the mud sedimentation tank should be cleaned regularly to prevent mud from flowing into the drainage ditch and sewer.
6. When using well points, each well point should work at the same time, so that the water level difference is controlled on the same side, and the fissure water in the soil layer is basically guaranteed not to enter the foundation pit. Seepage prevention measures should be taken for the drainage ditch on the slope of foundation pit, and waterproof mortar should be applied inside and outside. The dosage of waterproof mortar and waterproof powder is 5% of the cement dosage, so as to prevent the pumped water from infiltrating into the ground through the surface drainage ditch and returning to the foundation pit through soil cracks, thereby increasing the drainage capacity of the foundation pit.
7. In the process of precipitation, continuous power supply should be ensured, and special lines and special distribution boxes should be laid on site, using double lines. Designated personnel shall be on-site for 24-hour care, and regularly patrol each water pump to check whether the water level changes, whether the water level is lower than the water pump faucet and whether the water pump works normally to prevent the motor from burning out.
8. During the precipitation period, if there is a temporary power outage at the site, the owner shall notify the project department in advance and take certain measures to minimize the loss.
9, submersible pump should pay attention to the safety of electricity during work, often check whether there is grinding wire and leakage on the line, if there is any damage, repair the cable in time, or replace the cable.
10, pay attention to the weather forecast at ordinary times, prevent the weather from changing, increase the underground water inflow, and prepare two pumps for the foundation pit sump, one for standby, so as to prevent the water from flooding the foundation pit and causing heavy losses.
If this doesn't work, Luwen Construction Service Network has the following scheme. You can download it yourself if you want.
Construction organization design scheme of an open ditch reconstruction project in Zhengzhou
Chapter I Project Overview
Chapter II Construction Organization and Overall Construction Deployment
The third chapter, the main partial project construction method
The fourth chapter, time limit for a project schedule guarantee measures
Chapter V Protection Measures for Underground Pipelines
Chapter VI Technical Organization Measures to Ensure Project Quality
Chapter VII Technical Organization Measures to Ensure Safe Construction
Chapter VIII Organization and Management Measures to Ensure Civilized Construction
Chapter 9 General Construction Schedule
Chapter 10 General Layout of Construction