1 General Provisions
1.0.1 This specification has been formulated for the purpose to implement the state policy of technical economy to ensure engineering quality by selecting reasonable kinetic parameters and foundation form, thus making technology advanced, economic, safe and fit for purpose.
1.0.2 This specification applies for foundation design of various dynamic machines, namely:
(1) Piston compressor;
(2) Steam turbine unit and motor;
(3) Turbine compressor;
(4) Crusher and grinder;
(5) Impact machine (forging hammer and drop hammer);
(6) Hot dye forging press;
(7) Metal-cutting lathe.
This specification does not apply to foundation design of dynamic machine on building floors.
1.0.3 In addition to this specification, foundation design shall also meet other currently applicable state standards and codes.
2. Terminology and Signs
2.1 Terminology
2.1.1 Foundation Set
The entire dynamic machine foundation with all machines, aux. equipment and backfill on top.
2.1.2 Equivalent Load
Static load equivalent to dynamic load exerted on the original vibration system, adopted to facilitate analysis.
2.1.3 Frame Type Foundation
Foundation formed by connecting top layer beams/plates and columns and bottom plates.
2.1.4 Wall Type Foundation
Foundation formed by connecting top plates, walls and bottom plates.
2.1.5 Rigidity of Subsoil
The ability of foundation to resist deform, value equals to the ratio of force/torque exerted on foundation with line/angle deform caused thereby.
2.2 Signs
2.2.1 Action and action effect
Pz — Vertical interference force on machine
Px — Horizontal interference force on machine
P — Average designed static pressure on foundation bottom surface
Mφ — Rotary interference torque on machine
Mψ — Twisting interference torque on machine
Az — Vertical vibration line displacement at center of gravity of foundation set
Ax — Horizontal vibration line displacement at center of gravity of foundation set or that of foundation member
Aφ — Rotary vibration angle displacement of foundation
Aψ — Twisting vibration angle displacement of foundation
Axφ — Horizontal vibration line displacement of foundation top plane control point under the eccentric action by horizontal interference force Px, torque Mφ and vertical interference force Pz
Axψ — Vertical vibration line displacement of foundation top plane control point under the eccentric action by horizontal interference force Px, torque Mφ and vertical interference force Pz
ω — Circular frequency of interference force on machine
ωnz — Intrinsic vertical circular frequency of foundation set
ωnx — Intrinsic horizontal circular frequency of foundation set
ωnφ — Intrinsic rotary circular frequency of foundation set
ωnψ — Intrinsic twisting circular frequency of foundation set
ωn1 — Foundation set intrinsic circular frequency for horizontal rotary coupled vibration type I
ωn2 — Foundation set intrinsic circular frequency for horizontal rotary coupled vibration type II
a — Foundation vibration acceleration
V — Foundation vibration speed
2.2.2 Calculation Indices
Cz — Natural foundation compressive rigidity coefficient
Cφ — Natural foundation flexural rigidity coefficient
Cx — Natural foundation shear rigidity coefficient
Cψ — Natural foundation torsion rigidity coefficient
Cpz — Equivalent compressive rigidity coefficient of pile tip earth
Cpτ — Equivalent shear rigidity coefficient of earth layers around pile
Kz — Natural foundation compressive rigidity
Kφ — Natural foundation flexural rigidity
Kx — Natural foundation shear rigidity
Kψ — Natural foundation torsion rigidity
Kpz — Pile foundation compressive rigidity
Kpφ — Pile foundation flexural rigidity
Kpx — Pile foundation shear rigidity
Kpψ — Pile foundation torsion rigidity
ξz — Natural foundation vertical damping ratio
ξxφ1 — Natural foundation damping ratio for horizontal rotary coupled vibration type I
ξxφ2 — Natural foundation damping ratio for horizontal rotary coupled vibration type II
ξψ — Natural foundation twisting damping ratio
ξpz — Pile foundation vertical damping ratio
ξpxφ1 — Pile foundation damping ratio for horizontal rotary coupled vibration type I
ξpxφ2 — Pile foundation damping ratio for horizontal rotary coupled vibration type II
ξpφ — Pile foundation twisting damping ratio
fk — standard load bearing capacity for earth foundation
f — Designed load bearing capacity for earth foundation
[A] — Allowed vibration linear displacement for foundation
[V] — Allowed vibration speed for foundation
[a] — Allowed vibration acceleration for foundation
m — Mass of foundation set
2.2.3 Geometric parameters
A — Foundation bottom area
Ap — Pile cross section
I — Moment of inertia about axis through center of form of foundation bottom plane
J — Moment of inertia of foundation set about axis of center of gravity
Iz
—
Polar moment of inertia about axis through center of form of foundation bottom plane
Jz — Polar moment of inertia of foundation set about axis of center of gravity
h1 — Distance of center of gravity of foundation set to top plane of foundation
h2 — Distance of center of gravity of foundation set to bottom plane of foundation
2.2.4 Calculation Coefficients and others
αf — Dynamic reduction coefficient of earth foundation load bearing capacity
αz — Increase coefficient of earth foundation compressive rigidity by foundation burying depth action
αxφ — Increase coefficient of earth foundation shear, flexural and torsion rigidity by foundation burying depth action
βz — Increase coefficient of vertical damping ratio by foundation burying depth action
βxφ — Increase coefficient of damping ratio for horizontal rotary coupled vibration by foundation burying depth action
δb — Foundation burying depth ratio
3 Basic Design Requirements
3.1 General Requirements
3.1.1 Following information should be available at time of foundation design:
1) type of machine, rotation speed, power rating, size and outline/dimensions drawing;
2) weight of machine and position of center of gravity;
3) outline drawing of machine pedestal, aux. equipment, piping location; dimensions of pit, ditch and holes; thickness of grouting, positions of anchor bolts and embedded parts, etc.;
4) interference force and torque on machine and their directions;
5) positions of foundation and foundation drawing of neighboring buildings;
6) geological survey information and earth foundation kinetic testing information of construction site.;
3.1.2 Dynamic machine foundation should be separated from building foundation, upper structure and concrete ground surface.
3.1.3 When major vibration of machine exists due to connection with piping, vibration isolating measures shall be taken where piping contacts building.
3.1.4 When vibration of machine foundation adversely affects nearby personnel, precision equipment, instrumentation, factory production or buildings, vibration isolating measures shall be taken. The effect of vibration of low frequency machine and impact machine on plant house structure should meet Appendix A of this specification.
3.1.5 Dynamic machine foundation design must not create detrimental uneven subsidence.
3.1.6 When dynamic machine foundation and neighboring building foundation are on natural foundation, their burying depths can be at different elevations provided construction requirements can be met and backfill for this difference is well compacted.
3.1.7 When dynamic machine foundation sits on fairly integral rock, pile foundation can be adopted with the exception of dynamic foundation for forging hammers and drop hammers. In this case, foundation design shall meet Appendix B of this specification.
3.1.8 The distance between pedestal rim and foundation rim is preferably not less than 100mm. With the exception of forging hammer foundation, secondary grouting of thickness not less than 25 mm shall be provided beforehand under the machine pedestal. This should be fill-compacted by slight expansion concrete and combined with concrete foundation surface.
