基坑开挖换填施工方案1123 英文版.docx

1、基坑开挖换填施工方案1123 英文版Sokoto Cement Factory Project of the 17th Bureau, Chinese Railway Construction CompanyConstruction Schemes for Foundation pit Excavation And ReplacementComposed by： Editor： Chief editor： Fifth division of 17th Bureau of CRCC, manager department of the Sokoto Cement Factory Project,

2、 Nigeria 23th November 2104Contents1 Introduction 1.1 Basis for the composition 1.2 Principles for the composition 2.1 Location 2.2 Geographic report 2.3 Ground water and underground water. 3 Construction techniques and methods 3.1 Excavation of the foundation pit 3.1.1 Gradient of the foundation pi

3、t 3.1.2 The stability of the side slope 3.1.3 The form of excavation 3.1.4 Preparation for the excavation 3.1.5 Construction procedures 3.1.6 Methods 3.2 Gravel replacement 3.2.1 Construction material 3.2.2 Construction preparation 3.2.3 Techniques and constructional procedure. 3.2.4 Methods 4 Organ

4、ization of construction and logistic work 4.1 The managing system for construction organization. 4.2 Human resources for the construction 4.3 Logistic work 4.4 Technical guarantee 4.5 Quality and techniques standard and regulation 4.5.1 Quality standard 4.5.2 Quality monitoring organization 4.5.3 Ra

5、ising awareness for the importance of quality and professional skills. 4.5.4 Establishing quality management code. 4.6 Safety techniques measures 4.6.1 Safety regulations for mechanical construction 4.6.2 Traffic regulations 4.6.3 Safety regulations for filling construction. 4.7 Environment protecti

6、on measures 4.8 Construction during the rain season 4.8.1 Collecting weather data 4.8.2 Technical measures for drainage 4.9 Technical measures for sand storm 4.10 Contingency plan Construction Schemes for Foundation pit Excavation And Replacement1 Introduction1.1 Basis for the composition1.1.1 Geogr

7、aphic Report for the SOKOTO 3300T/D Clinker Dry Cement Production Line1.1.2 Drawings submitted by the Owner1.1.3 Unified Standard for Constructional Quality Acceptance of Building Engineering (GB50300-2001）。1.1.4 Code for Acceptance of Construction Quality of Foundation Engineering（GB50203-2002）。1.1

8、.5 Technical Specification for Ground Treatment of Building（JGJ79-002）。1.1.6 Technical Specification for Safety Operation of Construction Machinery（JGJ33-2001）。1.1.7 Code for Investigation of Geotechnical Engineering（GB50021-2001）。1.1.8 Status of the site and surrounding environment1.1.9 Calculation

9、 book for construction engineering1.2 Principles for the composition1.2.1 Significantly understanding the Basis for the composition, composing within the frame of the previous contract in the spirit of integrity, subjectivity and technical innovationality. Developing executable, scientific and effic

10、ient construction schemes in thorough consideration of the status of the site and other professional drawings2 . Introduction of the project2.1 LocationThe site on which the project is to be carried out locates in North Cement Factory, Sokoto, Nigeria, adjacent to the original cement production line

11、. The size of the site is 700 meters by 600 meters. With the higher South end and lower North end, the site consist of three stages:114m, 109m and 105m respectively.2.2 Geographic reportIn accordance with the geographic report provided by the Owner, the excavation involves three different types of s

12、oil.Artificial fill layer（Q4ml）（stratum number ）Soft soil that widely spreads around the site. Thickness: 0.311.5. Layer bottom elevation 88.85111.25m。Clinosol（Q4dl）（stratum number）The mix of gravelly soil and cohesive soil of brownish red color. Thickness: 0.2319.0m. Layer bottom elevation 82.1109.

13、99m。Cohesive soil（stratum number ）:the soil of light gray or yellow-gray color and good solidity. Medium/low compressibility. Characterized by the hard calcareous core. Thickness: 3.2524.83m，Layer bottom elevation75.2787.99m。2.3 Ground water and underground water.The site is going to use water from

14、underground with the depth of seven meters. Water is accessed to through well. The precipitation amount is significantly low except in raining season, which lasts from July to September. The drainage facilities are needed for the heavy precipitation. 3 Construction techniques and methods3.1 Excavati

15、on of the foundation pitIn consideration of the features of the soil and the geographic report, it was primarily concluded that layer-by-layer slope excavation shall be applied for all buildings and structures foundation pits. In case that there are buildings or structures that require support for t

16、he side slope, then other design should be made available for the construction of the support.3.1.1 Gradient of the foundation pit1) LateriteC=15Kpa =8.4 degree =19.7KN/M2) Shale C=20Kpa =11.4 degree =26KN/MIt is noted in the design drawings that the depth of the deep foundation pit H is no more tha

17、n 10 meters, which fall into two categories in terms of depth: 0mH5m，5mH10M。Based on the equation on the page 41 of Calculation book for construction engineering, the stable slope angle is calculated to be no more than 73 degrees. The gradient of the grading is set at 1/0.5 on account of the safety

18、coefficient and vehicular disturbance.Specific weight of the soil(kg/m3)Angle of gradient()Internal friction angle of the soil()Cohesive force of the soil(kg/m3)When the soil is in the state of limit equilibrium, the maximum height of the side slope (h) can be calculated through this formula.3.1.2 T

19、he stability of the side slopeThe safety coefficient is 1.13 based on the diagram below, which meets the requirement of the design and regulations. The text above: safety coefficient:1.13(Sweden finite slice method, total stress model )3.1.3 The form of excavationAccording to the design drawing, exc

20、avation of the foundation pit should be conducted in two different forms corresponding to different depth H: H5m，5mH10m. The details are presented below. In case that the excavation depth is more than 5 meters, a one-meter-wide platform should be created when the excavation reaches the cushion.3.1.4

21、 Preparation for the excavation1) Technical preparation：a) Elevation benchmark has been introduced to the construction area on the basis of elevation point given by the construction unit.b) Other preparation work include getting familiar with drawings and geographical status, planting axis-control p

22、ile, checking underground pipeline, machineries, completing disclosure work.2) Site preparation：a) Double-checking original control plants and benchmark, laying out positioning line, setting up perimeter for foundation pit excavation line and side slope line. The excavated laterite should be put in

23、a secure location within the site for the purpose of backfilling. Shale should be dumped into the dumping ground designated by the Owner.b) Properly preserving the foundation pit, examining the stability of the side slope before excavating, mending partially damaged side slope to ensure the stabilit

24、y.c) Organizing machineries and workforce to enter the site in a timely manner. Three excavators, one wheel loader and six tippers are to coordinate with the transportation. Excavator, wheel loader and tipper need to be checked before driving to ensure the reliability. All drivers should be properly

25、 licensed and all machine operators should observe relevant regulations for machine operating. After the vehicle is started, panel, light, alarm steering system, brake and other necessary parts should be examined for reliability and sensitivity. Fuel, lubricating oil and hydraulic oil also need to b

26、e checked to ensure the quality. Hinging parts, connectors require checking for loosening and hydraulic pressure system and hydraulic transmission system for leakage. Loading people in the grapple and violating driving regulation are strictly forbidden and subject to penalty.d) Construction schemes

27、are open to adjustment brought up by the changing situation on the site or major amendment to the drawing.3.1.5 Surveying and positioning risk eliminating ground clearing machinery entry excavating mending and maintaining side slope (continuing excavating and maintaining) flattening the foundation b

28、ase testing proceeding to next stageConstruction procedures 3.1.6 Methods1) After surveying and positioning, the excavation line on the hill crest is to be laid out and excavated by backhoe.2) The excavation work should be conducted layer by layer on both side of the side slope. To ensure the stabil

29、ity of the side slope, all excavated earthwork should be removed out timely. For rectangular or polylateral foundation pit, the number of excavator and other vehicles are to be determined by the size and depth of the foundation pit, 3) The elevation demands constant attention. accurate measurement b

30、y the dumpy level is required as it is about to reach the design elevation to prevent over-excavating. Standing within the turning radius of mechanical arm while it is operating is strictly prohibited. The excavating should be carried out in order and the excavated earthwork need to be removed as th

31、e excavation goes on. However, poorly protected worker are not allowed to work in the same spot as the machine. Significant illumination facilities should be in place if it is considered necessary to work at night. One specially designated technician should be responsible for conducting excavators a

32、nd other vehicles. The foundation pit needs to be thoroughly examined by an inspector for general stability status and unstable factors such as cracks and sliding. Any factor that might lead to major damage should be immediately reported to the project manager, while in the mean time the construction needs to be suspended for evacuation. 4) The tre