工程建设标准强制性条文CPECSB4房屋建筑部分（英文版）.doc

Section IVSurvey and Ground Foundation1. Ground Survey1.1 General RegulationsSurvey Specification for Rock and Soil Engineering GB 50021-941.1.12 Detailed survey shall provided detailed documents for rock engineering and technical parameters of rocks for design use in the light of different architectures or architecture groups. It shall also provide analysis and evaluation for rock engineering of architecture foundations and the proving of specific plans of foundation design, foundation treatment and the prevention and treatment of bad geological phenomenon as well. Followings are main works to be done:(1) To obtain general layout plan of architecture with coordinates and terrain, the cleaned ground level of architectures, the nature, scale and structural features of the architecture, the possible type and size of foundation, the estimated depth of foundation and the special requirements for foundation design etc.(2) To clarify the origin, type, distribution range, development trend and extent of hazards of bad geological phenomenon and to provide evaluation and technical parameters of rocks for the treatment.(3) To clarify the type, structure, thickness, slope and engineering features of each layer of soil within the area of the architecture, calculate and evaluate the stability and bearing force of the foundation.(4) For architectures need calculation for settlement, to provide parameters for calculation of foundation deformation.(5) For locations where the seismic intensity exceeds or equals to 6 magnitude, the category of ground soil and the category of ground shall be classified. For locations where the seismic intensity exceeds or equals to 7 magnitude, the earthquake liquefaction of saturated sand soil and saturated powder soil shall be judged and the index of liquefaction shall be calculated.(6) To clarify the concealment conditions for underground water. When making design for lowering water for foundation pits, it is also necessary to clarify the amplitude and regularity of water level changing and to provide information of stratum penetration.(7) To make judgement of the corrosion to construction materials and metals by environmental water and soil.(8) To make judgement of possibility of fluctuation of foundation soil and under ground water in construction period and in service period and their influence to the project, also suggest the measures for treatment.(9) For excavation of deep foundation pits, it is necessary to provide technical parameters regarding rock and soil required for making stable calculation and for the design of supports. Prove and evaluate the influence of foundation excavation and water lowering to neighboring projects.(10) To provide technical parameters regarding rock and soil for the design of foundation piles and to determine the load for single pile.1.1.15 The depth of bore hole in detailed survey shall be calculated from the bottom of foundation and its value shall meet following regulations:(1) For the foundation calculated according to the load, the depth of bore hole shall control the force-bearing layer of the foundation. When the bottom width of the foundation, b, is not more than 5m, the depth of the bore hole shall be three times the width of the bottom of strip foundation while for isolated foundation, it shall be 1.5 times. However, it shall not be less than 5m.(2) For foundations needed to check computations of deformations, the depth of control bore hole shall exceed the depth of settlement of foundation.(3) In case there is large area of stockpile load on the ground or there is soft sub base layer, the depth of bore hole shall be increased.1.1.16 The sampling and testing for detailed survey shall meet following regulations:(1) The number of taking-soil samples and the number for holes (wells) of testing at original position shall be determined according to the evenness and design requirements of the foundation. For buildings of Class 1 safety classification, it shall not be less than three per building.(2) For each location or each building of Class 1 safety classification, the samples of original soil of each main layer shall not be less than 6. The testing data at original position in the hole of same soil layer shall not be less than 6 groups.(3) In major force-holding layer of the ground, taking-soil samples or original position testing in bores shall be made for the sandwich layer or lens layer with thickness over 50cm.1.1.17 Construction survey shall be made in association with design organization and contractor in one of following cases:(1) For buildings of Class 1 or Class 2 safety classification, inspection of construction of foundation pits shall be made.(2) After excavation of foundation pits, in case the conditions of rock and soil are not in conformity with original survey information, construction survey shall be made.(3) If caves or earth holes in ground are developed, they shall be clarified and suggestion for treatment shall be put forward.(4) If in construction there is danger of instability of edge slope, it shall be clarified and monitored.1.1. 18 The arrangement of exploring points in detailed survey for high-story buildings shall meet following requirements:(1) Exploring points shall be arranged along the perimeters of the building. Corners and intermediate point shall also have exploring points.(2) The arrangement of exploring points shall meet the requirements for evaluation of stratum structure and evenness both from radial and longitudinal directions.(3) For buildings with special shape, the exploration points shall be arranged according to the special shape.(4) The number of exploring point for single high-story building shall not be less than four.3.7.2 The survey for excavation of foundation pits and for supporting engineering shall meet following requirements:(1) At initial stage of survey for proposed main building, the feasibility of supporting shall be preliminarily determined according to rock and soil engineering conditions. At stage of detailed survey, special survey shall be made to the projects need to support.(2) The range of survey shall be determined according to the depth of excavation and the rock and soil engineering condition of that location. Exploring points should be arranged out side of the boundary of excavation and to the depth of 12 times excavation depth. For soft soil, the scope of survey shall be extended appropriately. The depth of exploring points shall meet the requirements for checking at different limit conditions.(3) Effective stress strength parameter of soil or the parameter or anti-shear strength without draining water shall be put forward according to the structure of stratum and the nature of rock. And soil. The influence to the soil by changes in stress caused by construction, the changes in conditions of strain and the underground water shall be evaluated.(4) The features of under ground water within the area of excavation and nearby locations shall be clarified. It is also needed to clarify the influence to nearby buildings and facilities by changes in water level in construction. The estimation of the possibility of higher permeation and pipe surging shall be made. Measures for lowering water or isolating water in construction shall be suggested.(5) The existing status and characteristics of nearby buildings and facilities and their bearing capability for vibration and their displacement caused by construction shall also be checked and clarified.1.8.1 Survey for rock and soil engineering of piles or mounds shall include followings:(1) To clarify concealment condition of rock and soil and their physical and mechanical features, the concealment depth, thickness, property and their changes of force-bearing layer and soft sub base layer.(2) When ground rock is used as foundation force-bearing layer, it is necessary to clarify the structure, property, extent of weathering and the thickness of the ground rock.(3) The hydro-geological conditions and the corrosions to pile and mound material caused by under ground water shall be clarified.(4) To evaluate the feasibility of sinking-pile. To prove the construction conditions for pile or mound and their influence to the environment.6.2.2 In rock and soil engineering survey, if there is stratum, which contains water, under ground water level shall be measured.8.2.4 Exploratory boring shall meet following regulations:(1) The recovery drilling depth of non-continuous core-taking drilling shall be less than 1m for spiral exploratory boring, while for rock core boring, it shall be less than 2m.(2) For the boring to verify natural humidity of stratum, it shall be drilled in a dry way above the level of under ground water. When it is necessary to drill with added water or with circulation liquid, it shall use double-layer rock core pipe for drilling.(3) The rock core sampling rate in rock core boring shall not be less than 80% for general rock and not less than 65% for broken rock.(4) For fix-direction drilled bores, the inclination of the bore shall be measured section by section. The precision of measurement for inclination angle and orientation shall be respectively 0.1, 3.0.8.2.5 Records for field boring shall be made by personnel specially trained. The records shall be true and made timely and prepared as per each section. It is strictly prohibited to write afterwards. Specification for Engineering Geological Survey of Soft Soil Area JGJ 83-916.2.1 For the survey of foundation pits in soft soil area, care shall be taken in the excavation area to the displacement of earth caused by changes in stress field of earth and due to the nature of fluid of soft soil. Relevant measures and parameters for the bad phenomenon such as rebound of foundation bottom soil, side displacement and settlement of soil body in slope shall be put forward so as to provide information for the construction design of foundation excavation.6.2.2 Before foundation excavation, the locations of existing facilities of buildings, under ground structures and piping within the affected area shall be verified. The influence to the nearby environment shall be estimated and necessary precautions for prevention and monitoring shall be provided.1.2 Soil of Special NatureSpecification for Rock and Soil Engineering Survey GB 50021-945.7.3 The engineering geological survey and investigation in expansion rock and soil area shall include followings:(1) To verify nature, geological era, origin, forming shape, distribution and appearance nature of color, texture and crack, etc.(2) To classify the unit of landforms and the type of ground. Verify the situation of shadow landslide, land cracks, stormed crack, micro landforms and vegetation.(3) To investigate the situation of drainage and accumulation of surface water, the type of underground water, water level and the regularity of its change.(4) To collect local meteorological information about waterfalls, evaporation, temperature, ground temperature, dry season and wet season, duration of draught and to verify the extent of influence of atmosphere.(5) To investigate local experience of construction.5.7.5 For the depth of bore hole, apart from the depth for foundation and the depth for additional load, it shall also exceed the depth of atmosphere influence. For general bore hole, it shall not be less than 5m.The control bore hole, it shall not be less than 8m. Note: The depth of atmosphere influence refers to the effective depth of soil deformation of rising or falling under the action of natural climate such as factors of rain, evaporation and ground temperature.Technical Specification for Architecture in Area of Expansion Soil GBJ112-872.3.1 To evaluate the ground of expansion soil, it is necessary to verify the distribution and the condition of terrain and landforms of expansion soil in construction area and make a comprehensive evaluation on the basis of free expansion rate and the engineering geological features. When it is necessary, verification of mineral composition of soil and other testing shall be made.Specification for Architecture in Area of Wet-sinking Yellow Soil GBJ 25-902.1.1 Engineering geological survey shall verify following contents and in the light of the requirements for the building to make evaluation for the location and ground and to propose measures for treatment of the ground.(1) Age and origin of yellow soil stratum.(2) Thickness of wet-sinking yellow soil layer.(3) The changes of wet-sinking coefficient to the depth.(4) The plan layout of the type and class for wet-sinking.(5) Possibility of rising or falling of under ground water level and other engineering geological conditions.1.3 Results of SurveySpecification for Rock and Soil Engineering Survey GB 50021-9412.4.2 The contents of the report on the result of rock and soil engineering survey shall be determined according to the requirements of the task, the stage of the survey, geological conditions and the characteristics of the project. It shall include:(1) Purpose, requirement and task of the survey;(2) Summary of proposed project;(3) Method of survey and the arrangement of survey work;(4) Description and evaluation of ground landforms, terrain, stratum, geological structure, nature of rock and soil, underground water and bad geological phenomenon etc.(5) Evaluation of suitability and stability of the ground;(6) Analysis and selection of rock and soil parameters;(7) Schemes for rock and soil utilization, treatment and reformation;(8) Pre-forecasting and monitoring of possible problems of rock and soil in construction and in service period and proposing precautions;(9) Report shall be attached with drawings:(a) Layout plan of exploration points;(b) Column drawing of engineering geology;(c) Section of engineering geology;(d) Chart of test results at original position;(e) Chart of test results in roomsSpecification for Survey of Rock and Soil Engineering for High-story Building JGJ 72-907.0.1 The report on the survey of rock and soil engineering for high-story building shall include following main contents and basic requirements:(1) Bad geological phenomenon of the ground shall be described. The stability of the location and the ground under static condition shall be analyzed and proved. In the area where the seismic intensity is equal to or over 6 magnitude, the type of ground soil, the category of the ground shall be judged. For the area where the seismic intensity is equal to or over 7 magnitude, cracking displacement, liquefaction and seismic falling shall be analyzed, proved and judged. The suitability of the whole ground shall be clearly concluded.(2) Stratum structure and physical and mechanical property of rock and soil shall be described. Quantitative and qualitative evaluation shall be made for the evenness, strength and characteristic of deforming shall be made.(3) Hydrogeological conditions, concealment situation and amplitude of changes of under ground water shall be described. Their influence to the stability of foundation, basement and to the edge slope in construction shall be evaluated and the precautions proposed.(4) The plan for foundation shall be analyzed and proved. For the plan of natural foundation, force bearing layer and the buried depth of foundation shall be proposed. Bearing load and settlement shall be analyzed and calculated. For the plan for piles, the type of pile, force bearing layer at pile end, bearing load of the soil at pile end, friction force of soil around pile and singe pile bearing load and the possibility of sinking the pile shall be analyzed. When it is necessary, settlement of pile shall be analyzed. Other analysis and proving of appropriate foundation plans.2. Ground Design2.0 General RulesDesign Specification for Architecture Ground and Foundation GBJ 7-892.0.2 According to the safety class of the building and the extent of influence to the superstructure caused by ground deformation under long-term loading, the ground design shall meet following regulations:(1) Class 1 buildings and Class 2 buildings beyond the scope listed in Table 2.0.2 shall be calculated according to ground deformation. When making calculation, the requirements for ground load shall also be met;(2) The Class 2 buildings listed in Table 2.0.2 shall still make calculation for deformation in one of following cases:(a) The standard value of ground bearing load is less than 130kPa and the shape is complicate;(b) There is excessive uneven settlement of the ground caused by stockpiling load on the foundation and on nearby ground or by greater difference of loads on neighboring foundations;(c) There is possibility of inclination of buildings on soft soil foundations due to short distance;(d) There is back filled material of large thickness or uneven thickness in the ground and its curing by self-weight has not been completed.For Class 2 building and Class 3 buildings under other conditions, deformation calculation may not be made subject to the regulations for bearing load is met.(3) Stability shall be calculated for high-story buildings with horizontal load and for buildings built on slope.The Scope of Class 2 Architectures for which Ground Deformation Calculation MayNot Be Made Table 2.0.2Condition of main force bearing layers of groundStandard value of ground bearing load60fk8080fk100100fk130130fk160160fk200200fk300Gradient of each soil layer (%)55101010Type of architectureBlock bearing structure, frame structure (number of story)555667Notes:1. Main force bearing layers of ground refer to layers with depth of 3b (b is width of foundation bottom) under strip foundation and 1.5b under