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Review of Causes of Foundation
Failures and Their Possible
Preventive and Remedial
Measures
by
Dr. Amit Srivastava
Associa...
Contents
I. Introduction
II. Load transfer failures
III. Drag down and heave
IV. Collapsible soils
V. Lateral loads
VI. Co...
Contents
VIII.Water level fluctuation
IX. Earthquake
X. Vibration effect
XI. Foundation failure due to landslide/ slope in...
 Foundations of engineering constructions are systems that act
like interface elements to transmit the loads from superst...
 The objective of foundation is to transfer the load of
superstructure to the foundation soil on a wider area.
 The unce...
Figure 1. East side of Transcona elevator following foundation failure
Transcona elevator
• Under such circumstances, the most commonly
adopted remedial measure to rectify the problem is
underpinning.
• Underpinn...
Figure 2. Foundation Underpinning by hydraulic jacking and transfers
loads to screw foundations installed into stable stra...
• In plastic soils, new settlements (drag down) are often
accompanied by upward movements and heave some
distance away.
• ...
Figure 3. Pictorial representation of structural damage caused
by drag down and heave
Types of settlement
Damages due to expansive soils
(i) Soil stabilization with lime, lime-fly ash, Portland cement, etc.
(ii) Control of soil moisture using plastic fabric u...
• They are deposits of fine grained particles transported by wind
and are characterized by constituent parts with an open ...
A ‘loess avalanche’ in Shanxi, China which killed 23
people due to structural & foundation failure of small
houses on the ...
Figure 6. Collapse of the soil in The terraces, Glenwood, Colorado was
causing settlement of the concrete retaining-wall f...
• By keeping a check on the structural design, i.e., loads and
foundation selection (mat foundations minimize the risk of
...
• During an earthquake the foundation of the building moves with
the ground and the superstructure and its contents shake ...
• Lateral movement in soil is possible when there is removal of
existing side support adjacent to a building. There is exc...
Figure 7. (a) Building Failure during 1964 Niigata, Japan Earthquake, (b) Failure of lower
San Fernando dam in 1971 (c) Re...
Figure 13. Typical example of overturning of a building due to liquefaction of
the foundation soil during the Kocaeli eart...
Liquefaction mitigation measures
(i) Soil Improvement Options
(a) Densification, Deep Dynamic Compaction
(b) Hardening Tec...
(i) Proper planning of Subsurface Investigation,
(ii) Analysis and Design and
(iii) Construction Control and Supervision.
...
• There are two common sources of construction errors,
i.e.,
(I) Temporary protection measures (Error relating to
temporar...
Foundation not aligned properly
Punching failure of foundation Lack of proper investigation
Few cases indicating major Con...
Figure 9. (a) apartment building was constructed, (b) it was decided for an
underground garage to be dug out. The excavate...
• There is no remedy for such massive failures but definitely
preventive measures in terms of “supported excavation
system...
Figure 10. (a) Design details of soil nail wall section (view
from E) (b) work executed for supporting vertical excavation...
• Footing resting on different type of soil, different bearing
capacity and unequal load distribution will result in the
u...
Figure 11. Different strategies applied to prevent the tower from
collapse
• Rise in GWT reduces the bearing capacity of the soil and on
the other hand rapid fall in the GWT causes ground
subsidenc...
Figure 12: Formation of sinkhole due to ground water table
fluctuation
• Construction activities such as blasting, pile driving, dynamic
compaction of loose soil, and operation of heavy constru...
• Monitoring and control of ground and structure vibrations
provide the rationale to select measures for prevention or
mit...
• Foundation failure due to rapid movement of landmass over a
slope results when a natural or man-made slope on which
stru...
Figure 14. Foundation failure of existing facility due to landslide/
slope instability
• Modifying the geometry of the slope,
• Controlling the groundwater,
• Constructing tie backs,
• Spreading rock nets,
• P...
• One of the major causes of foundation failure due to uplift is
presence of expansive soil beneath the foundation.
• Swel...
• The paper reviewed and discussed the various causes of
foundation failure as well as their possible preventive or
remedi...
THANK YOU!
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Review of Causes of Foundation Failures and Their Possible Preventive and Remedial Measures by Dr. Amit Srivastava

A brief description of foundation failures and their possible preventive and remedial measures.

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Review of Causes of Foundation Failures and Their Possible Preventive and Remedial Measures by Dr. Amit Srivastava

  1. 1. Review of Causes of Foundation Failures and Their Possible Preventive and Remedial Measures by Dr. Amit Srivastava Associate Professor, Department of Civil & Environmental Engineering The NorthCap University, HUDA Sector 23-A Gurgaon - 122017.
  2. 2. Contents I. Introduction II. Load transfer failures III. Drag down and heave IV. Collapsible soils V. Lateral loads VI. Construction error VII. Unequal support
  3. 3. Contents VIII.Water level fluctuation IX. Earthquake X. Vibration effect XI. Foundation failure due to landslide/ slope instability XII. Foundation failure due to uplift XIII.Conclusion Contents
  4. 4.  Foundations of engineering constructions are systems that act like interface elements to transmit the loads from superstructure to, and into, the underlying soil or rock over a wider area at reduced pressure.    Engineering structures despite being constructed with adequate strength and safety measures do fail or collapse.  “Failure is an unacceptable difference between expected and observed performance.” – Council of Forensic Engineering, ASCE Introduction
  5. 5.  The objective of foundation is to transfer the load of superstructure to the foundation soil on a wider area.  The uncertainties for which factor of safety is provided in geotechnical design include (a) the natural heterogeneity or inherent variability (b) measurement error, and (c) model transformation uncertainty.  Classic examples of Bearing capacity failures: Transcona Grain elevator in 1913 and Fargo Grain Elevator in 1955. Load transfer failures
  6. 6. Figure 1. East side of Transcona elevator following foundation failure Transcona elevator
  7. 7. • Under such circumstances, the most commonly adopted remedial measure to rectify the problem is underpinning. • Underpinning is accomplished by extending the foundation in depth or width so that it either rests on a more supportive soil stratum or distributes its load across a greater area. • Use of steel piers, helical anchors and micro piles are common methods in underpinning. Preventive measures and remedies
  8. 8. Figure 2. Foundation Underpinning by hydraulic jacking and transfers loads to screw foundations installed into stable strata
  9. 9. • In plastic soils, new settlements (drag down) are often accompanied by upward movements and heave some distance away. • In swelling and shrinking soils, hot dry wind and intense heat will often cause the soil to shrink beneath the foundation. • Uneven saturation of the soil around foundation (located in expansive soils) can cause the soil to heave as it expands and contracts after drying. • Similar problem of heave and contraction is observed when foundation is placed in extremely cold condition (below freezing point). Drag down and heave
  10. 10. Figure 3. Pictorial representation of structural damage caused by drag down and heave Types of settlement
  11. 11. Damages due to expansive soils
  12. 12. (i) Soil stabilization with lime, lime-fly ash, Portland cement, etc. (ii) Control of soil moisture using plastic fabric underneath the foundation, (iii) A thin coat of bitumen will drastically reduce the shear-force between the pile surface and the soil and reduce the negative skin friction, (iv) Ignoring active zone of expansion and contraction by placing footing at deeper depth or providing pile/ belled piers, (v) Heavy structure to overcome swell pressure, (vi) Ice adhesion and resulting uplift can be avoided by using granular backfill around the foundation walls or footing pedestals Preventive measures and remedies
  13. 13. • They are deposits of fine grained particles transported by wind and are characterized by constituent parts with an open packing arrangement, which forms a meta-stable state that can collapse to form a closer packed, more stable structure of significantly reduced volume. • Collapse in such deposits can be triggered by either increasing the load on the soil or by wetting it. • A collapse condition can lead to structure failure, landslides (depending on the topography), and tsunamis (if the soil collapses into a body of water). COLLAPSIBLE SOILS
  14. 14. A ‘loess avalanche’ in Shanxi, China which killed 23 people due to structural & foundation failure of small houses on the slope & at the foot. Other Failures Collapsible Soil: LOESS
  15. 15. Figure 6. Collapse of the soil in The terraces, Glenwood, Colorado was causing settlement of the concrete retaining-wall foundations Collapsible Soil: LOESS
  16. 16. • By keeping a check on the structural design, i.e., loads and foundation selection (mat foundations minimize the risk of differential settlements) • Landscape irrigation should be restricted or eliminated, excellent drainage facilities should be underlain with an impermeable liner to prevent water from seeping into the soil • Popular ground modification treatments for such soils include pre- wetting of the soil, dynamic compaction, Vibro-floatation, Vibro- compaction, Stone/cement columns, treating the soil with calcium chloride and/or sodium silicate solutions in order to introduce cementing that is insoluble, etc. Preventive measures and remedies
  17. 17. • During an earthquake the foundation of the building moves with the ground and the superstructure and its contents shake and vibrate in an irregular manner due to the inertia of their masses (weight). • Damage to foundations & structures may result from different seismic effects: (i) Ground failures (or instabilities due to ground failures), (ii) Vibrations transmitted from the ground to the structure, (iii) Ground cracking, (iv) Liquefaction, (v) Ground lurching, (vi) Differential settlement, (vii) Lateral spreading, and (viii) Landslides. Failure due to Earthquake
  18. 18. • Lateral movement in soil is possible when there is removal of existing side support adjacent to a building. There is excessive overburden on backfill or lateral thrust on the backside of a retaining wall • Lateral movement is also observed during earthquake when structure fails due to lateral movement of soil beneath the foundation following liquefaction • Classic examples of such failures are: (a) major damage to thousands of buildings in Niigata, Japan during the 1964 earthquake, (b) Failure of Lower San Fernando dam which suffered an underwater slide during the San Fernando earthquake, 1971. Earthquake & Liquefaction
  19. 19. Figure 7. (a) Building Failure during 1964 Niigata, Japan Earthquake, (b) Failure of lower San Fernando dam in 1971 (c) Retaining wall failure (d) Failure of Showa bridge during 1964 Niigata earthquake in Japan Earthquake & Liquefaction
  20. 20. Figure 13. Typical example of overturning of a building due to liquefaction of the foundation soil during the Kocaeli earthquake, Turkey, August 17, 1999, Magnitude 7.4
  21. 21. Liquefaction mitigation measures (i) Soil Improvement Options (a) Densification, Deep Dynamic Compaction (b) Hardening Technique, Grouting, (ii) Structural Option, Piles or Caissons extending below the liquefiable soil (iii) Quality Assurance , in taking mitigation measures
  22. 22. (i) Proper planning of Subsurface Investigation, (ii) Analysis and Design and (iii) Construction Control and Supervision. (iv) For small scale damages underpinning of structures is suggested. Additional measures and remedies
  23. 23. • There are two common sources of construction errors, i.e., (I) Temporary protection measures (Error relating to temporary shoring, bracings and temporary coffer dams), (II) Foundation work itself. Construction error
  24. 24. Foundation not aligned properly Punching failure of foundation Lack of proper investigation Few cases indicating major Construction failure
  25. 25. Figure 9. (a) apartment building was constructed, (b) it was decided for an underground garage to be dug out. The excavated soil was piled up on the other side of the building (c) Final failure of building •This paper presents a classic case of poor construction practice due to which foundation failure of a building in Shanghai, China took place Construction error
  26. 26. • There is no remedy for such massive failures but definitely preventive measures in terms of “supported excavation system” for “deep excavation problems” can be adopted to avoid such failures. • Soil nailing is the latest and most widely used technique for supporting the vertical excavation near an existing building. • A classic application of soil nailing technique is reported in which soil nail support of excavation system for the embassy of the Peoples republic of China in the United States was carried out. Preventive measures and remedies
  27. 27. Figure 10. (a) Design details of soil nail wall section (view from E) (b) work executed for supporting vertical excavation using soil nailing technique Soil Nailing Technique
  28. 28. • Footing resting on different type of soil, different bearing capacity and unequal load distribution will result in the unequal settlement or what we call as differential settlement. • The Tower of Pisa in Italy is a classic case study. Unequal support
  29. 29. Figure 11. Different strategies applied to prevent the tower from collapse
  30. 30. • Rise in GWT reduces the bearing capacity of the soil and on the other hand rapid fall in the GWT causes ground subsidence or formation of sinkholes due to increased overburden effective stress value. • Formation of sinkhole is another major cause of foundation failure due to increased water usage, altered drainage pathways, overloaded ground surface, and redistributed soil. • According to the Federal Emergency Management Agency, the insurance claims for damages as a result of sinkholes has increased 120% from 1987 to 1991, costing nearly $100 million. Water level fluctuation
  31. 31. Figure 12: Formation of sinkhole due to ground water table fluctuation
  32. 32. • Construction activities such as blasting, pile driving, dynamic compaction of loose soil, and operation of heavy construction equipment induce ground and structure vibrations. • Ground vibrations from construction sources may affect adjacent and remote structures in three major ways, i.e., (I) structure vibration with/without the effect of resonance structure responses, (II) dynamic settlement due to soil densification and liquefaction, (III) pile driving and accumulated effects of repeated dynamic loads. Vibration effect
  33. 33. • Monitoring and control of ground and structure vibrations provide the rationale to select measures for prevention or mitigation of vibration problems, and settlement/damage hazards. Active or passive isolation systems are adopted in this regard. Preventive and remedial measures
  34. 34. • Foundation failure due to rapid movement of landmass over a slope results when a natural or man-made slope on which structure exists becomes unstable. • The major causes of slope instability/ landslide can be identified as (i) Steep slope, (ii) Groundwater Table Changes / heavy rainfall, (iii) Earthquakes and other vibrations, and, (iv) removal of the toe of a slope or loading the head of a slope Foundation failure: slope instability
  35. 35. Figure 14. Foundation failure of existing facility due to landslide/ slope instability
  36. 36. • Modifying the geometry of the slope, • Controlling the groundwater, • Constructing tie backs, • Spreading rock nets, • Providing proper drainage system, • Provision of retaining walls, etc. • Soil nailing Technique Preventive and remedial measures
  37. 37. • One of the major causes of foundation failure due to uplift is presence of expansive soil beneath the foundation. • Swelling clays derived from residual soils can exert uplift pressures, which can do considerable damage to lightly- loaded or wood-frame structures. • In case of pile foundations that are used to resist the uplift forces due to wind loads, such as, in transmission line towers, high rise buildings, chimney, etc., the available uplift resistance of the soil becomes the one of the most decisive factor in defining the stability of foundation. Foundation failure due to uplift
  38. 38. • The paper reviewed and discussed the various causes of foundation failure as well as their possible preventive or remedial measures through case studies. • The work will be useful for practicing engineers in identifying the potential foundation problem in advance and taking necessary and appropriate action for mitigation purpose. Conclusion
  39. 39. THANK YOU!

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