1.0.1 This code is formulated with a view to enabling design and construction of rock-socketed piles for harbour engineering to achieve advanced technology, economy and rationality, safety and usability, and guaranteeing the engineering quality.
1.0.2 This code is applicable to design, construction, quality control and load test of rock-socketed piles for harbour engineering. Rock-socketed piles for other similar engineering may refer to it.
1.0.3 Load acted on plies and its effect combination shall comply with the relevant requirements of the current professional standards "Load Code for Harbour Engineering" (JTJ 215), "Code for Pile Foundation of Harbour Engineering" (JTJ 254) and "Design and Construction Code for Open Type Wharf on Piles" (JTJ 291), etc.
1.0.4 The design and construction of rock-socketed piles for harbour engineering shall not only comply with this code, but also those in the current relevant ones of the nation.
2 Terms and Symbols
2.1 Terms
2.1.1 Cast-in-place rock-socketed piles
Piles that are formed through pouring and the pile tip is embedded into bed rock to anchor.
2.1.2 Cast-in-place anchor-bolt rock-socketed piles
Piles that are embedded into rock mass via anchor bolt to enable cast-in-situ pile and bed rock to anchor.
2.1.3 Precast imbedded rock-socketed piles
Piles that the precast pile tip is embedded into bed rock to anchor.
2.1.4 Precast core-column rock-socketed piles
Piles that precast pile and bed rock are anchored through concrete pouring by drilling bed rock in precast pile core.
2.1.5 Precast anchor-bolt rock-socketed piles
Piles that are embedded into rock mass via anchor bolt to enable precast pile and bed rock to anchor.
2.1.6 Combined rock-socketed piles
Piles that are formed through the combination of precast core-column rock-socketed mode or cast-in-place rock-socketed mode and anchor-bolt rock-socketed mode.
2.2 Main Symbols
A——Sectional area of pile body or area of pile tip
AS——Sectional area of anchor bolt steel bar
D——Diameter of pile body or anchor hole
G——Pile gravity
Le——Effective anchorage length of anchor bolt
Lj——Thickness of pile body passing through the ith layer of soil
Md——Design value of bending moment of pile body at bed rock top surface
Pd——Design value of anchor bolt pull-out force
Pk——Standard value of ultimate pull-out force of anchor bolt
Qcd——Design value of axial compression bearing capacity of single pile
Qck——Standard value of axial ultimate compression capacity of single pile
Qtd——Design value of axial pull-out bearing capacity of single pile
Qtk——Standard value of axial pull-out ultimate bearing capacity of single pile
Vd——Design value of shear force of pile body at bed rock top surface
d——Internal diameter of pile, diameter of rock-socketed segment or diameter of anchor bolt steel bar
fck——Standard value of axial compressive strength of concrete
frc——Standard value of uniaxial compressive strength of saturated rock
fy——Design value of tensile strength of anchor bolt steel bar
fyk——Standard value of yield strength of anchor bolt steel bar
hr——Rock-socketed depth
qfi——Sandard value of ultimate lateral resistance of the ith layer of soil for single pile
qfk——Standard value of bond strength
γ——Partial coefficient
μ——Circumference of pile body
ε——Calculation coefficient of resistance
3 General Requirements
3.0.1 Design and construction of rock-socketed piles shall be provided with the following data:
(1) Service requirements;
(2) Hydrology, weather, topography, environment and water depth data;
(3) Geological conditions and engineering geological evaluation;
(4) Necessary load test and standing stability test condition;
(5) Investigation condition of obstructions affecting construction;
(6) Performance of main construction equipment, etc.
3.0.2 The type of rock-socketed piles shall be determined through technical and economic proof according to service requirements and geological conditions such as buried depth of bed rock. Rock-socketed piles may adopt cast-in-place rock-socketed piles, cast-in-place anchor-bolt rock-socketed piles, precast imbedded rock-socketed piles, precast core-column rock-socketed piles, precast anchor-bolt rock-socketed piles or combined rock-socketed piles. Rock-socketed piles may be vertical piles or batter piles.
3.0.3 Bearing capacity of rock-socketed piles shall be calculated respectively according to pile body structure strength and supporting capacity of foundation to pile based on different load carrying conditions.
