1 General Provisions
1.0.1 This code is prepared with a view to safety applicability, advanced technology, reasonable economy, guaranteed quality and environmental protection during construction of building foundation engineering.
1.0.2 This code is applicable to construction of building foundation.
1.0.3 The construction of building foundation engineering shall ensure safety and quality and shall adjust measures to local conditions and save resources.
1.0.4 The construction of building foundation engineering shall comply with not only this code but also the requirements of relevant current national standards.
2 Terms
2.0.1 Subsoil
Soil mass or rock mass that supports the foundation.
2.0.2 Foundation
A structural component that transfers external load borne by upper structure and deadweight of upper structure to subsoil.
2.0.3 Composite foundation
Subsoil with the loads borne by reinforcement (which is formed by reinforcing or replacing partial soil mass) and subsoil around together.
2.0.4 Pile foundation
Foundation composed of pile that is imbedded into subsoil and cushion cap that is connected with pile top together.
2.0.5 Dynamic consolidation
The subsoil treatment method to tamp subsoil by repeatedly lifting the hammer to high place and making it fall freely, which impacts the subsoil and gives it vibration energy.
2.0.6 Dynamic replacement
The subsoil treatment method to form dense pier by repeatedly lifting the hammer to high place and making it fall freely to form tamping pit on the ground and then repeatedly tamping sand-gravels, steel slags and other granules filled in the tamping pit alternately.
2.0.7 Grouting
The treatment method to cement loose soil particles or cracks into an integral whole by injecting solidifiable grout into rock-soil mass gaps with the help of the hydraulic, pneumatic or electrochemical principle.
2.0.8 Preloading
The subsoil treatment method to carry out preloading or vacuum preloading to the subsoil to accelerate subsoil consolidation.
2.0.9 Vibrofloatation
The subsoil treatment method to form composite foundation composed of original subsoil and pile, which is formed by making the sand soil layer dense under combined action of horizontal vibration of vibroflot or backfilling gravels after pore-forming in soft soil layer.
2.0.10 Post base-grouting bored-pile
Bored pile that carry out high-pressure grouting to pile tip after pile-forming through grouting pipe preset in pile shaft and pile tip grouting machine.
2.0.11 Excavation engineering
A generic term for such engineerings as enclosure, shoring, dewatering, water-proof and seepage-proof engineering, reinforcement, earthwork excavation and backfilling adopted for building underground structure.
2.0.12 Retaining structure of foundation pit
Structural system composed of retaining wall, circuit purlin, support (anchor), support column (column pile) and other systems.
2.0.13 Secant pile
Row-pile wall formed by mutual lapping and cutting of earlier constructed bored piles and later constructed bored piles.
2.0.14 Steel and soil-cement mixed wall
Composite soil retaining and water intercepting structure formed by inserting steel into three-axis soil-cement mixing piles lapped continuously.
2.0.15 Diaphragm wall
Underground wall formed by putting reinforcement cage and pouring concrete or putting precast reinforced concrete slab wall into machined trench.
2.0.16 Cutter joint
Joint of diaphragm walls formed by cutting concrete in previous trench with slot milling machine.
2.0.17 Joint pipe (box)
Temporary steel pipe (box) adopted to form joint of diaphragm wall between unit trenches.
2.0.18 Soil-cement gravity retaining wall
Gravity shoring structure formed through mutual lapping of soil-cement mixing piles.
2.0.19 Soil-nailed wall
Shoring structure composed of sidewall soil of foundation pit reinforced with soil nail and protective covering.
2.0.20 Top-down method
Construction method that makes construction of underground structure from top to bottom and foundation pit excavation alternately with a part or all of main underground structure as shoring structure.
2.0.21 Open caisson
Underground structure formed by manufacturing well bore on the ground and sinking it to underground predetermined depth through soil sampling in well.
2.0.22 Pneumatic caisson
Underground structure formed by manufacturing well bore with horizontal sealing plate on the ground to form pneumatic pressure work room under sealing plate, carrying out excavation through adding air into work room to balance water and soil pressure, and then sinking it to underground predetermined depth.
2.0.23 Groundwater control
Measures such as water drainage, dewatering, water insulation and recharging adopted in excavation engineering in order to guarantee smooth implementation of excavation engineering and to reduce the influence of construction on surrounding environment.
2.0.24 Curtain for cutting off water
Curtain wall vertical water interception body used to obstruct or decrease groundwater from flowing into excavation through sidewall and bottom of foundation pit and to control groundwater lowering outside foundation pit.
2.0.25 Non-reinforced spread foundation
Strip foundation under wall or independent foundation under column composed of brick, rubble, concrete or rubble concrete, lime soil, concrete and other materials and configured with no reinforcement.
2.0.26 Reinforced concrete spread foundation
Cast-in-place reinforced concrete independent foundation under column and reinforced concrete strip foundation under wall.
2.0.27 Raft and box foundation
Raft foundation refers to continuous flat-slab or beam-slab reinforced concrete foundation. Box foundation refers to monolithic precasted single-layer or multi-layer reinforced concrete foundation composed of reinforced concrete bottom plate, top plate and internal and external vertical and horizontal walls.
2.0.28 Bermed excavation
The excavation method to leave soil around in pit, excavate soil in middle part of foundation pit out first to form pot-shaped soil mass and form underground structure and support in middle part of foundation pit and then excavate soil around foundation pit out.
2.0.29 Island excavation
The excavation method to excavate soil around foundation pit out first to form island-shaped soil mass and then excavate soil in middle part of foundation pit out in excavation engineering with shoring structure.
2.0.30 Anchor arm(rope)
The tension member formed by drilling hole in soil (rock) mass, inserting such tensioned reinforcement as reinforcement or steel strand, grouting cement mortar in anchorage section to anchor in stabilized soil (rock) layer and connecting another end with structural body.
2.0.31 Composite soil nailing wall
Shoring structure composed of mixing pile, soil nail and sprayed concrete surface.
3 Basic Requirements
3.0.1 The quality inspection requirements for materials and products used in the construction of building subsoil, foundation, foundation pit and slope engineerings, which shall comply with current national standard and the design requirements.
3.0.2 Before construction of building subsoil, foundation, foundation pit and slope engineerings, the following data shall be provided:
1 Geotechnical investigation report;
2 Design documents required for construction of building subsoil, foundation, foundation pit and slope engineerings;
3 Data about buildings (structures), underground pipelines and obstacles within the influence scope of proposed engineering construction;
4 Construction organization design and special construction and monitoring schemes.
3.0.3 The axis locating point and elevation bench mark for construction of building subsoil, foundation, foundation pit and slope engineerings shall be protected properly after rechecking and shall be re-measured regularly.
3.0.4 Before construction of foundation pit engineering, the preparation work shall be done well and such conditions as hydrogeological conditions of engineering field, adjacent underground pipelines, nearby buildings (structures) and underground obstructions shall be analyzed. Corresponding measures shall be taken to protect adjacent underground pipelines and buildings (structures).
3.0.5 During construction of building subsoil, foundation, foundation pit and slope engineerings, the influence of groundwater, surface water and spring tide shall be controlled.
3.0.6 Anti-freezing and drainage measures shall be taken for construction of building foundation engineering in winter or rainy season.
3.0.7 It is strictly forbidden to stack earthwork within the influence range of foundation pits (trenchs) and buildings (structures).
3.0.8 Excavation of foundation pit (trench) shall meet the following requirements:
1 The construction load for foundation pit (trench) periphery and sloping platform shall be controlled in accordance with the design requirements;
2 During excavation of foundation pit (trench), the layer thickness and temporary side slope gradient shall be determined through calculation according to soil quality;
3 Excavation construction conditions of foundation pit (trench) shall meet the design requirements.
3.0.9 Where dangers occur during construction, the emergency measures shall be timely taken to control the danger case.
3.0.10 Where cultural relics and historic sites are encountered during construction, the construction shall be stopped immediately and such case shall be reported to related department.
3.0.11 During construction of building subsoil, foundation, foundation pit and slope engineerings, the construction records shall be made well.
1 General Provisions
2 Terms
3 Basic Requirements
4 Ground Construction
4.1 General Requirements
4.2 Soil and Lime-soil Foundation
4.3 Sand and Sandstone Foundation
4.4 Flyash Foundation
4.5 Dynamic Consolidation Foundation
4.6 Grouting Consolidated Foundation
4.7 Preloading Foundation
4.8 Vibration Impact Foundation
4.9 High Pressure Jet Grouting Foundation
4.10 Soil-cement Mixed Pile Foundation
4.11 Soil-lime Compacted Column Composite Foundation
4.12 Cement Flyash Gravel Pile Composite Foundation
4.13 Tamping Soil-cement Pile Composite Foundation
4.14 Sandstone Column Composite Foundation
4.15 Foundation on Collapsible Loess
4.16 Foundation on Frozen Soil
4.17 Foundation on Expansive Soil
5 Foundation Construction
5.1 General Requirements
5.2 Non-reinforced Spread Foundation
5.3 Reinforced Concrete Spread Foundation
5.4 Raft and Box Foundation
5.5 Reinforced Concrete Precast Pile
5.6 Cast-in-situ Pile with Slurry Protection Wall
5.7 Press-grouting Concrete Pile Drilled by Long Spiral
5.8 Tube-sinking Cast-in-situ Pile
5.9 Dry Drilling Cast-in-situ Pile
5.10 Steel Pile
5.11 Anchor Pile
5.12 Foundation on Rock-anchor System
5.13 Sunk Well and Caisson
6 Construction of Foundation Pit Retaining
6.1 General Requirements
6.2 Contiguous Bored Pile Wall
6.3 Sheet Pile Wall
6.4 Secant Pile Wall
6.5 Soil Mixed Wall
6.6 Diaphragm Wall
6.7 Gravity Cement-soil Wall
6.8 Soil Nailing Wall
6.9 Strut
6.10 Anchor Arm (Cable)
6.11 Foundation Pit Support Combined with Main Structure
7 Groundwater Control
7.1 General Requirements
7.2 Drainage Galleries
7.3 Dewatering
7.4 Cut-off Drain
7.5 Recharge
8 Construction of earthwork
8.1 General Requirements
8.2 Excavation of Earthwork
8.3 Excavation of Rock Foundation Pit
8.4 Stacking and Transportation of Earthwork
8.5 Backfilling of Earthwork
9 Slope Construction
9.1 General Requirements
9.2 Bolt-shotcrete Support
9.3 Retaining Wall
9.4 Excavation of Slope
10 Safe and Green Construction
Explanation of Wording in this Code
List of Quoted Standards
