Construction scheme
(A) the construction survey scheme
1. Building axis and elevation control:
After the city survey brigade locates the building and determines the relevant leveling points, our construction unit will establish the construction axis control network and leveling points in time based on this. The main building has three horizontal control axes (1.9. 14 axis) and two vertical control axes (A and D axis). The annex has two horizontal control axes, namely 1. 1 1 axis, and two vertical control axes, namely, H axis and L axis. In this way, the axis control network is established to ensure that the axis deviation does not exceed the allowable range of the specification. After the leveling point is determined, the elevation within the construction scope shall be measured in time, and the elevation point shall be marked on the buildings or structures that are stable, easy to measure and have no settlement.
2. Foundation and main project construction survey
The axis and elevation of the building are mainly controlled by theodolite and level in foundation engineering construction. In the construction of the main project, in order to improve the measurement accuracy and reduce the measurement deviation, the laser plumb instrument is used to carry out construction measurement with theodolite and level. When the main body is constructed, the control axis will be transferred to the construction layer from bottom to top in turn with laser plumb instrument. After inspection and confirmation, the axis will be measured with theodolite to ensure the correct axis position.
3. The elevation transfer in the main project construction:
During construction, the elevation will be transferred from the lower level to the upper level, so that the elevation of floors, doors and windows, interior decoration and other projects can meet the design requirements. Elevation transfer adopts steel rule direct measurement method, and at least three elevation datum points of+/-0.000 are set on the first floor, and elevation is transferred upwards according to these three datum points during construction.
4. Building settlement observation:
According to the layout requirements of settlement observation points in construction drawings, correctly bury settlement observation points. When measuring the elevation of the settlement observation point for the first time, the accuracy of the initial measurement must be ensured, and its elevation should be determined after two observations in the same period. During the construction of the main body of the project, settlement observation shall be conducted once every layer is completed, and settlement observation shall be conducted once a month after the completion of the main body of the project until the project is completed. In the process of settlement observation, if abnormal settlement is found, you should contact the design institute in time. After the building is completed, the settlement observation should still be carried out once a month in the first year, once every two months in the second year, once every six months in the third year and once a year in the fourth year until the settlement is stable. Settlement observation is a long-term systematic observation work. In order to ensure the correctness of the observation results, four tests should be carried out as far as possible:
(1) The fixed personnel observed and sorted out the results.
(2) Fixed use of level and spirit level.
(3) Use fixed leveling points.
(4) Observe according to the specified date, method and route.
(2) Foundation earthwork excavation and deep foundation pit support scheme
1. Foundation earthwork
(1) The earthwork excavation of this project is divided into three sections, and the earthwork excavation volume is about 26000m3 (including sloping and ramp). See Shi Jie 3 for the plane position, and see Shi Jian for the absolute elevation corresponding to each 0.000 section. For the foundation excavation, 2 sets 1m3 hydraulic excavators will be used for the construction machinery, and 8 sets 10t dump trucks will spoil the soil. The foundation excavation sequence is _ _ main building construction first. After the main structure of _ _ section is completed, it will enter the main entrance awning of _ _ section and the podium foundation excavation of _ _ section. After the main structure of _ _ section is completed, it will enter the foundation pit construction of _ _ section underground pool.
(2) Earthwork layered construction
Due to the different excavation depths of each component of this project (section-7.25m, section-6.95m, section-6.35m, local-7.35m) all exceed the maximum excavation depth of ordinary excavators. At the same time, combined with the elevation of foundation pit, slope steps and excavator production efficiency, this project is planned to be excavated in two layers. The first floor _ section is-3.25m, _ section is-2.95m, _ section is-3.35m; The second layer is excavated to the pit bottom elevation of each section.
(3) Slope setting shall be determined according to the excavation depth of each section of the project, and the slope setting shall be determined according to the geological exploration report and the surrounding conditions of the construction site, with reference to the specification requirements and relevant regulations. Because the geological exploration of this project is unknown, according to the good geological conditions in this area (except for the local soil nailing wall in the southeast corner of section _), the first-floor slope is 1: 0.5, and the second-floor slope is 1: 0.75. Add a platform with the width of 1m between floors. See the schematic diagram of foundation pit excavation section on page 1 1 for details.
(4) the opening of the ramp
Due to the design requirements and site restrictions, this project is divided into three sections and constructed in different periods, so it is necessary to set up three first-floor ramps with a slope of 1: 6 and a width of 6m. After foundation pit excavation, in addition to the requirements of civil construction, the ramp should be backfilled to ensure construction safety.
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