This article is about SAES-Q-009 which is about Concrete Retaining Walls and download SAES-Q-009 PDF for Engineers, supervisors and project managers, QCs, QC Supervisors. This is saudi aramco standards of Civil Engineering based on international codes and standards and useful for Civil Construction knowledge to get job as engineers, QC Supervisors and QC managers, Engineering managers and technicians.
SAES-Q-009 PDF Download
SAES-Q-009Concrete Retaining Walls
The SAES-Q-009 Standard specifically focuses on the design and specifications for reinforced concrete retaining walls. It outlines the mandatory requirements that should be followed during the construction process. However, if other materials are required for the retaining walls instead of reinforced concrete, the guidelines provided in SAES-M-100, which is the Saudi Aramco Building Code, should be referred to for the appropriate design and construction requirements.
4. Design of Concrete Retaining Walls
The design and specifications for the construction of reinforced concrete retaining walls should meet the requirements for their intended use, following commonly accepted engineering practices, Saudi Aramco Engineering Standard SAES-Q-001, and the guidelines specified in the following paragraphs.
4.1 Soils Analysis
4.1.1 A thorough soils analysis must be conducted to determine the characteristics of the soil, including subsurface materials, maximum allowable soil bearing pressure, recommended depth of the footing, unit soil weight, internal friction angles, soil shearing capacity, groundwater location, and other provisions as described in paragraph 11, Appendix A of Saudi Aramco Engineering Standard SAES-A-113.
4.1.2 In the case of minor retaining walls located in remote areas or retaining walls where soil data is available for the adjacent area, a detailed soils analysis may be waived with the approval of the Supervisor, Civil Engineering Unit, Rotating Equipment & Civil Engineering Division, Consulting Services Department. In such instances, the design should establish and document the allowable soil characteristics for the design.
4.2 Retaining Wall Stability
4.2.1 The bottom of the footing should be positioned at least 600 mm below the finished grade surface of the ground in front of the footing, unless a detailed soils investigation indicates otherwise.
4.2.2 Retaining walls should be designed to withstand anticipated loads, including surcharge loads, wheel loads, earthquake/seismic loads as specified in Saudi Aramco Engineering Standard SAES-A-112, construction loads, lateral pressures from water-filled cracks in the backfill, and any other loads resulting from special circumstances.
4.2.3 The retaining wall should be designed to withstand the full active soil pressure. Effective drainage facilities must be provided to drain the fill material behind the retaining wall. Drainage can be achieved using weepholes with crushed rock or coarse gravel French drains placed at suitable intervals, or longitudinal drains placed behind the wall with outlets at the ends of the wall. Alternatively, commercial drainage/filter materials specifically designed for this purpose may be used. If crushed rock or coarse gravel is used for weepholes or French drains, it must meet specific criteria as per the relevant guidelines and standards.
These requirements ensure that the design and specifications for reinforced concrete retaining walls take into account soil characteristics, stability against anticipated loads, and the provision of adequate drainage facilities.
4.2.4 In counterfort walls, each pocket formed by the counterforts should have a minimum of two drains.
4.2.5 Retaining wall footings subjected to water pressure must be designed to resist uniformly distributed uplift equal to the full hydrostatic pressure.
4.2.6 The minimum safety factor against overturning about the toe and sliding should be 1.5. The weight of soil or passive earth pressure for the first two feet from the backfill in front of the retaining wall should not be considered when calculating these safety factors. Both friction resistance and passive pressure can be used in combination to determine the resistance to sliding. In cases where the sliding resistance is low, a key may be provided to increase the sliding resistance to meet the minimum factor of safety.
4.2.7 For retaining walls constructed on or at the base of slopes, a general slope stability analysis should be performed. A minimum factor of safety of 1.25 is required for long-term stability.
4.2.8 In areas with soft soils or potentially liquefiable soils, retaining walls may be supported on piles or stone columns.
These additional requirements provide specific guidelines for the design of counterfort walls, footings subject to water pressure, safety factors against overturning and sliding, slope stability analysis, and the use of alternative support methods in areas with soft or potentially liquefiable soils.
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FAQs about SAES-Q-009 PDF
A soils analysis provides essential information about the characteristics of the soil, including bearing capacity, groundwater location, and internal friction angles. This information is crucial for designing a stable and reliable retaining wall.
In some cases, such as minor retaining walls in remote locations or when sufficient soil data exists for adjacent areas, a detailed soils analysis may be waived with the approval of the Supervisor. However, allowable soil characteristics for design must be established and documented by the design team.
The bottom of the footing should be at least 600 mm below the finished grade surface of the ground in front of the footing. However, this depth may vary depending on the findings of a detailed soils investigation.
Retaining walls should be designed to withstand various loads, including surcharge loads, wheel loads, seismic loads, construction loads, lateral pressures from water-filled cracks in the backfill, and any other loads specific to the project.
Adequate drainage facilities must be provided to effectively drain the fill material behind the retaining wall. This can be achieved through the use of weepholes, French drains with crushed rock or coarse gravel, longitudinal drains, or commercial drainage/filter materials designed for this purpose.
The minimum safety factor against overturning about the toe and sliding should be 1.5. The weight of soil or passive earth pressure for the first two feet from the backfill should not be considered in computing these safety factors. Additional measures, such as friction resistance, passive pressure, or the use of keys, may be employed to meet the minimum factor of safety.
Yes, for retaining walls constructed on or at the base of slopes, a general slope stability analysis should be performed. A minimum factor of safety of 1.25 is required for long-term stability.
In areas with soft soils or potentially liquefiable soils, retaining walls may be supported on piles or stone columns to enhance stability and prevent failure.
Dynamic analysis procedures should be employed when designing support structures or foundations for centrifugal rotating machinery with a horsepower greater than 500. For units with less than 500 horsepower, a detailed dynamic analysis may not be required unless specified by the Manufacturer.
In the absence of a detailed dynamic analysis, the foundation weight should be at least three times the total machinery weight for units greater than 500 horsepower. For units less than 500 horsepower, the foundation weight should be at least five times the total machinery weight, unless specified by the Manufacturer.
To maintain equipment alignment and minimize relative deflections, all coupled elements of the machinery train should be mounted on a common foundation or support structure. However, auxiliary equipment may be installed separately.
Foundations for heavy machinery should be independent of adjacent foundations and buildings. Concrete slabs or paving adjacent to the foundation should have a minimum 12 mm isolation joint to allow for movement. Adequate spacing between foundations should also be ensured to prevent transmission of detrimental vibrations
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