Code of practice for design and construction of machine foundations, Part 5: Foundations for impact machines and other than hammer (forging and stamping press, pig breaker, drop crusher and jolter)
1987 Edition

IS 2974 Part 5 – Scope & Essential Data for Machine Foundations

This section defines the applicability of the code to foundations for impact machines excluding elevator or hoist towers, focusing on forging presses, pig and scrap breakers, jolters, and similar equipment.

Highlights:

• Applies to foundations of impact machines other than hammers.
• Emphasizes the need for manufacturer-supplied machine data for accurate foundation design.

Essential Machine Data (Clause 3.1):

Numerical Rounding:

• Follow IS 2-1960 for rounding off calculated or test values to match the significant figures of the input data.

This ensures the foundation design properly accommodates both static and dynamic forces for safety and performance.

flowchart TD
    A[Manufacturers' Data] --> B{Machine Type}
    B --> C[Forging and Stamping Press]
    B --> D[Pig and Scrap Breaker]
    B --> E[Jolter]
    C --> F[Pressure, Stroke, Weights, Load-Time Curve, Dynamic Moment]
    D --> G[Ram Weight, Fall Height, Scrap Weight]
    E --> H[Jolting Table Weight, Frequency, Stroke, Pressure]

IS 2974 Part 5 – Definitions and Required Data Overview

• Terminology: Refer to IS 2974 Part 1 (1982) for foundational terminology related to machine foundations.

• Machine Data Needed (Clause 3.1): For forging, sheet metal, and stamping presses:

  • Layout and outline drawings
  • Anchor bolt specifications
  • Press pressure (p) and stroke (S)
  • Weights: crosshead (we), total machine (wp), and material handled (wm)
  • Load-time pulse curve (p vs t)
  • Dynamic forces and moments for eccentric presses (M)
  • Steel column size and height

  For pig and scrap breakers:

  • Ram weight and drop height
  • Pig scrap mass
  • Construction loads

  For jolters:

  • Weight of jolting table including charge (wt)
  • Anvil weight (W)
  • Frequency of jolts (blows per minute)
  • Stroke or fall height (S)
  • Maximum steam or air pressure (p)

• Soil Information (Clause 3.2):

  • Soil profile and properties extending to three times the foundation depth or to hard strata
  • Soil investigations following IS 1892 (1979) and dynamic soil properties per IS 5249 (1977)
  • Seasonal groundwater table levels

Reference Table for Key Symbols and Units

IS 2974 Part 5: Essential Soil and Machine Data for Design

Soil and Site Data (Clause 3.2)

• Soil profile depth should be at least three times the mean plan dimension of the foundation or extend to hard strata.
• Geotechnical investigations must comply with IS 1892-1979; dynamic soil characteristics are to follow IS 5249-1977.
• Seasonal fluctuations of the groundwater table must be documented.

Machine Design Data (Clause 3.1)

• For pig and scrap breakers, additional parameters such as ram weight, fall height, and construction loads are necessary.
• Jolters require data including jolting table plus charge weight, anvil weight, jolting frequency, stroke length, and maximum steam or air pressure.

Design Notes (Clause 4.7.1)

• Jolter foundations are designed following Clause 4.4, considering the combined moving weight of table plus charge.

Summary Table of Key Parameters

IS 2974 Part 5 – Summary of Design Foundations Criteria

Critical Design Inputs (Clause 3)

• Soil Data:
  • Soil profile extending to at least three times the mean foundation dimension or to the hard strata.
  • Dynamic soil characteristics obtained per IS 5249-1977.
  • Seasonal water table positioning.
• Machine Data:
  • Manufacturer’s layout and anchor bolt details.
  • Pressing pressure (p), stroke (S).
  • Weights: crosshead (we), gross (wp), material to be forged (wm).
  • Load-time curve (p vs t), dynamic forces and moments (M).
  • Jolting frequency, fall height, and maximum operating pressure.

Design Methodology (Clause 4.7.1)

• Jolter table foundations consider the combined moving weight (table + charge).
• Follow Clause 4.4 for dynamic load considerations and design steps.

Key Parameters and Formulas

Design Considerations

• Employ dynamic soil parameters from IS 5249 in foundation analysis.
• Incorporate load-time variation effects in dynamic force calculations.
• Design anchor bolts and embedment per machine layout.
• Account for groundwater influence on soil bearing pressures.

flowchart TD
    A[Machine Data] --> B[Dynamic Loads (p, M)]
    C[Soil Data] --> D[Soil Profile & Dynamic Properties]
    B --> E[Foundation Design]
    D --> E
    E --> F[Foundation Dimensions and Reinforcement]
    F --> G[Construction and Detailing]

Refer to IS 2974 Part 1 for comprehensive design procedures.

IS 2974 Part 5: Principal Design Guidelines Summary

Soil Data Requirements (Clause 3.2)

• Soil profile and characteristics must be established to a minimum depth of three times the mean plan foundation dimension or to the hard strata.
• Investigations should conform to IS 1892-1979 for general soil properties and IS 5249-1977 for dynamic soil characteristics.
• Seasonal variations in the groundwater table should be recorded.

Design Considerations (Clause 4.3)

• Alignment of Centers of Gravity: The machine and foundation centers of gravity should ideally align vertically through the foundation’s centroid.
• Avoidance of Resonance: The natural frequency of the foundation-soil system (w_n) must not be an integer multiple of the machine’s operational frequency (w_m).

Resonance Avoidance Condition

[ w_n \neq n \times w_m \quad \text{for} \quad n = 1, 2, 3, \ldots ]

Where:

• w_n = natural frequency of foundation-soil system
• w_m = machine operating frequency

Summary Table of Design Criteria

flowchart TD
    A[Start: Machine & Foundation Design] --> B[Soil Investigation per IS 1892]
    B --> C[Dynamic Soil Properties per IS 5249]
    C --> D[Water Table Assessment]
    D --> E[Center of Gravity Vertical Alignment]
    E --> F{Check Natural Frequency (w_n)}
    F -->|No Resonance| G[Proceed with Foundation Design]
    F -->|Resonance| H[Modify Design to Avoid Resonance]

IS 2974 Part 5 – Permissible Stress Guidelines

• Steel and Concrete: Utilize the full permissible stresses outlined in IS 456:1978 when dynamic loads are accounted for with appropriate dynamic and fatigue factors (Clause 4.2.1).

• Soil Stress Limits:

  • Under combined static and dynamic loading, the soil stress should not exceed 80% of the allowable static soil stress as per IS 6403:1981 (Clause 4.2.3).
  • For seismic design scenarios, permissible soil stresses may be increased following IS 1893:1984 (Clause 4.2.4).

Reference Standards for Permissible Stresses

Soil Stress Limit Formula Under Dynamic Loading

[ \sigma_{soil, dynamic} \leq 0.8 \times \sigma_{soil, static} ]

Where:

• ( \sigma_{soil, static} ) = allowable soil stress per IS 6403
• ( \sigma_{soil, dynamic} ) = permissible soil stress under combined loads

flowchart TD
    A[Load Type] --> B{Static Load}
    B --> C[Use IS 6403 Soil Stress]
    B --> D{Dynamic Load}
    D --> E[Apply Dynamic & Fatigue Factors]
    E --> F[Use full IS 456 stresses for steel/concrete]
    E --> G[Limit soil stress to 0.8 × IS 6403 value]
    B --> H{Seismic Load}
    H --> I[Increase soil stress per IS 1893]

IS 2974 Part 5 – General Design Provisions

Soil Data (Clause 3.2)

• Soil profile and characteristics must be determined to a depth of at least three times the mean plan foundation dimension or to the hard strata.
• Soil investigations should follow IS 1892-1979; dynamic soil properties should comply with IS 5249-1977.
• Seasonal groundwater table levels should be documented.

Design Criteria (Clause 4.3)

• The center of gravity of the machine and its foundation should be vertically aligned through the foundation centroid.
• To prevent resonance, the ratio of natural frequency of the foundation-soil system (w_n) to machine operating frequency (w_m) must not be an integer:

[ \frac{w_n}{w_m} \neq \text{integer} ]

Foundation Design Notes

• Jolter table foundations consider the combined weight of the machine plus the charge (Clause 4.7.1).
• Refer to IS 2974 Part 1 for definitions and additional design criteria.

Frequency Relation Summary

graph TD
    A[Machine Center of Gravity] -->|Vertical Alignment| B[Foundation Centroid]
    C[Operating Frequency (w_m)] -->|Resonance Avoidance| D[Natural Frequency (w_n)]
    D -->|Non-Integer Multiple| C

Dynamic Analysis According to IS 2974 Part 5 – Essential Formulas and Guidelines

Dynamic Magnification Factor (Clause 4.5.2)

For stamping machines situated on hard rock where pressure-time data is unavailable:

[ n = \frac{V}{Wh} ]

Where:

• (V = 2 m f_m S) represents the velocity at mid-stroke
• (W) is the machine weight excluding the crosshead
• (h = \frac{E A}{h}), with (A) as cross-sectional area and (h) the height of anchor columns
• (f_m) is the operating frequency in cycles per second
• (S) is the stroke length

For large eccentric presses, dynamic loads are approximated as:

• Dynamic moment = 5 times the normal torque
• Dynamic force = 5 times the centrifugal force at the flywheel center

Foundation Motion Amplitude (Clause 4.4.1)

For impact durations considered negligible but blows periodic:

[ A = \frac{2 I}{k m} \sin \left(\pi \frac{T_1}{T}\right) ]

Where:

• (A) is the amplitude of foundation motion
• (I) is the impact momentum
• (k) is the subgrade stiffness
• (m) is the combined mass of machine and foundation
• (T_1) is the period of blow occurrence
• (T) is the natural period of the foundation-soil system

If (I) is unknown, approximate:

[ A = \frac{2 w v}{\omega_p} \sin \left(\pi \frac{T_1}{T}\right) ]

Where:

• (w) is the falling weight
• (v) is terminal velocity
• (\omega_p) is the natural frequency

Dynamic Force Calculation with Non-Negligible Impact Duration (Clause 4.4.2)

• Step 1: Determine the natural period (T) of the foundation-soil system (refer IS 2974 Part 1).
• Step 2: Obtain dynamic magnification factor (y) from the ratio (t_1 / T) (see Fig. 1 in IS 2974).
• Step 3: Calculate the dynamic force:

[ F_a = y \times \alpha \times P_a ]

Where (\alpha) is the fatigue factor and (P_a) the peak force.

IS 2974 Part 5 – Design Guidelines for Forging and Stamping Press Foundations

Manufacturer Data Requirements (Clause 3.1a)

For forging, sheet metal, and stamping presses, collect:

• Layout and installation drawings
• Anchor bolt and embedded part details
• Press pressure (p) and stroke (S)
• Crosshead weight (we) and gross machine weight (wp)
• Weight of material forged (wm)
• Load-time relationship (p vs t)
• Dynamic forces and moments for eccentric presses (M)
• Steel column dimensions

Press Types (Clause 4.5.1)

• Hydraulic
• Eccentric
• Friction

Dynamic foundation analysis is performed according to Clause 4.4, considering vibration and impact forces.

Typical Design Parameters

Foundation Design Procedure

1. Compute static loads: sum of wp, we, and wm.
2. Determine dynamic loads using p vs t curves.
3. Include eccentric moments (M) where applicable.
4. Design anchor bolts and embedments per layout plans.
5. Perform vibration analysis as specified in Clause 4.4.

flowchart LR
  A[Manufacturer Data] --> B[Static Load Calculation]
  B --> C[Dynamic Load Analysis]
  C --> D[Moment Computation]
  D --> E[Foundation Design]
  E --> F[Anchor Bolts & Embedments]
  E --> G[Vibration Assessment]

Reference: IS 2974 (Part 5)

IS 2974 Part 5 – Design Aspects of Foundations for Pig and Scrap Breakers

Required Data (Clause 3.1b):

• Layout and installation drawings
• Anchor bolt and embedded part details
• Ram weight and drop height
• Pig scrap weight
• Constructional loads

Principal Design Parameters

Impact Force Estimation Formula

[ F = \frac{W_r \times g \times h}{\Delta t \times v} ]

Where:

• (F) = Impact force in Newtons
• (W_r) = Ram weight (kg)
• (g) = Acceleration due to gravity (9.81 m/s²)
• (h) = Drop height (m)
• (\Delta t) = Impact duration (seconds), from manufacturer or testing
• (v = \sqrt{2gh}) = Velocity just before impact

Design Considerations

• Apply dynamic load factors based on impact pulse characteristics.
• Anchor bolts and embedded parts must conform to manufacturer details.
• Foundations designed to resist dynamic forces and moments.
• Soil bearing capacity must be verified for foundation sizing.

Summary of Design Inputs

flowchart TD
    A[Manufacturer Data] --> B[Ram Weight & Drop Height]
    A --> C[Anchor Bolt Details]
    A --> D[Layout Drawings]
    B --> E[Impact Force Calculation]

IS 2974 Part 5 – Jolters Foundation Design Highlights

Design Basis (Clause 4.7.1)

• Jolter foundations follow the general foundation design procedure in Clause 4.4.
• The moving weight (W_m) is the combined mass of the jolting table plus the charge.

Manufacturer Data Needed (Clause 3.1)

• Layout and outline drawings
• Anchor bolt and embedded parts details
• Weight of jolting table with rated charge (W_t)
• Weight of anvil (W_a)
• Jolting frequency (blows per minute)
• Stroke or fall height (S)
• Maximum steam or compressed air pressure (p)

Design Considerations

• Dynamic forces depend on jolting frequency and stroke length.
• The load-time relationship (pressure vs time) must be accounted for.
• Foundation blocks must resist dynamic loads generated by jolting actions.

Dynamic Load Estimation Formula

[ F_d = W_t \times g + m \times a ]

Where:

• (W_t) = Total weight of table plus charge
• (g) = Gravitational acceleration (9.81 m/s²)
• (m) = Mass of moving parts
• (a) = Acceleration due to jolting (estimated from stroke and frequency)

Summary Table of Jolter Parameters

This information supports dynamic load computations and foundation design per IS 2974 Parts 1 and 5.

flowchart TD
    A[Manufacturer Data] --> B[Calculate Moving Weight (W_t)]
    B --> C[Dynamic Load Calculations]

IS 2974 Part 5 – Construction Guidelines for Block Foundations

Highlights from Clause 5.8 (Construction Details)

• Foundation bolts must be firmly anchored to ensure load transfer and structural stability.
• For jolter foundations, total moving weight includes the jolting table plus the charge.
• Design procedures adhere to Clause 4.4 dynamic load considerations.

General Construction Requirements:

• Use plain or reinforced concrete complying with IS 456 (Code of Practice for Plain and Reinforced Concrete).
• Conduct soil investigations as per IS 1892 and evaluate dynamic soil properties according to IS 5249.
• Foundation depth and dimensions are dictated by soil conditions and load demands.

Construction Details Summary

Jolter Foundation Total Moving Weight Formula:

[ W_{total} = W_{jolter\ table} + W_{charge} ]

Where:

• (W_{total}) is the combined moving mass for design
• (W_{jolter\ table}) is the jolter table weight
• (W_{charge}) is the charge mass

Load Transfer Diagram

flowchart TB
    A[Load on Jolter Table] --> B[Total Moving Weight]
    B --> C[Foundation Block]
    C --> D[Soil Bearing Capacity]

Note: For detailed anchorage, embedment, and reinforcement specifications, refer to IS 456 and project-specific structural drawings.