Case Study 180-2

 

Consolidation of Native soils under and
adjacent to Fill Materials caused
Foundation Failure

 

Installed By:

Atlas Piers of Utah
Sandy, Utah

 

 

Consolidation of Native Soils under and adjacent to
Fill Materials caused Foundation Failure.

The Church

Description of the Building: The church was built on a steel reinforced, concrete foundation consisting of a perimeter footing, stem wall and a floor slab. The structure is of wood frame construction with an exterior covering of brick veneer. The building has a metal roof.

Distress Distress Observed: Differential settlement of the perimeter walls caused extensive distress. At the entrances there where large cracks in the masonry and stressed soffits were evident. The perimeter foundation pulled away from the concrete floor slabs leaving ¾ to 1-½ inch separations. The interior distress included separations of up to 2 inches between the exterior wall and adjoining interior walls with vertical displacements on the order of ½ inch. Ceiling separations of one inch were evident.

Cause of the Problem: Based upon soil tests, the engineers determined that settlement was the result of consolidation of the existing soils adjacent to a sand fill directly under the building. Of equal or greater significance was the presence of loose to medium dense native granular soils beneath the fill material. These soils showed a dramatic increase of soil moisture as a result of several things including landscape irrigation, and poor drainage. This increase in moisture led to consolidation of these low density soils causing settlement.

Engineered By: Kleinfelder, Inc. Salt Lake City, Utah
Repaired By: Atlas Piers of Utah, Sandy, Utah
Average Drive Force: 57,000 pounds Average Lift Force: 29,100 pounds
Average Factor of Safety: 95% above actual lift force

Number of Piers: 64   Amount of Lift: Up to 4"    Average Depth: 86’ to 151’

 

Workers preparing the structure

Worker

RAPID INSTALLATION TO A DEPTH OF OVER 150 FT!

Hand excavations permit the installation of the Atlas Resistance Piers. This means no heavy equipment and minimal disruption to the landscape. The piers are driven to a suitable load bearing stratum using quiet and smooth hydraulic cylinders.

These photographs show the workers preparing the structure the installation and restoration using Atlas Resistance Piers.

Interior classroom door

LOOK AT THIS!

These photographs show an interior classroom door before and after restoration. The structure is gently returned to as close as possible to original elevations using a series of hydraulic rams.

Interior classroom door

 

Complete restoration of the 2 inch separation

SUCCESS!

There was a significant lateral movement between the exterior walls and the interior partition walls. Notice the success! As the structure was lifted, lateral forces were applied to bring

The walls together. The photographs show nearly complete restoration of the 2 inch separation between the walls.

Complete restoration of the 2 inch separation between the walls

25 ton hydraulic rams

Here the lift at pier number fourteen is 4 inches! The structure was gently lifted using a series of 25 ton hydraulic rams. In addition, hydraulic rams applied lateral forces to the structure to close the separations between the exterior and interior walls. Below shows the lift along the west wall.

The lift along the west wall.

 

Atlas Resistance Piers

PARTIAL PIER INSTALLATION RESULTS

FACTOR OF SAFETY RESULTS
Location Lifting Force-lb. Driving Force-lb. Ultimate Cap.-lb. Working F.S. Ultimate F.S. Approx.
Lift - in.		 Depth to Bearing
Pier #51 30,900 58,030 85,000 1.88:1 2.75:1 1/2" 151’ – 7"
Pier #52 25,750 58,030 85,000 2.25:1 3.30:1 1/2" 150’ – 8"
Pier #53 25,750 58,030 85,000 2.25:1 3.30:1 5/8" 146’ – 7"
Pier #54 25,750 58,030 85,000 2.25:1 3.30:1 3/4" 140’ – 5"
Pier #55 28,480 58,030 85,000 2.01:1 2.95:1 1" 135’ – 11"
Pier #56 28,480 58,030 85,000 2.01:1 2.95:1 7/8" 130’ – 11"
Pier #57 26,265 58,030 85,000 2.21:1 3.24:1 5/8" 136’ – 4"
Pier #58 15,450 58,030 85,000 3.76:1 5.50:1 1/4" 136’ – 10"

FACTOR OF SAFETY ANALYSIS

Factor of Safety Analysis Graph

 

 

ATLAS RESISTANCE PIERS

PARTIAL INSTALLATION SUMMARY
Pier Installation Log

Pier
Section

 Location and driving force -- pounds
Pier #51 Pier #52 Pier #53 Pier #54 Pier #55 Pier #56 Pier #57 Pier #58
Sect. #1

Sect. #2

Sect. #3

Sect. #4

Sect. #5

 0

13,264

13,264

6,632

18,238

 0

14,922

13,264

8,290

7,461

 0

14,093

8,290

6,632

9,119

 0

14,922

6,632

7,461

8,290

 0

13,264

5,803

6,632

8,290

 0

9,948

4,974

6,632

6,632

 0

13,264

5,803

5,803

5,803

 0

11,606

8,290

12,435

13,264
Sect. #6

Sect. #7

Sect. #8

Sect. #9

Sect. #10

 13,264

8,290

14,922

12,435

11,606

 8,290

15,751

14,093

26,528

9,948

 8,290

9,119

11,606

10,777

15,751

 10,777

13,264

9,119

5,803

9,948

 9,948

9,948

10,777

8,290

18,238

 9,948

10,777

9,948

8,290

15,751

 14,922

14,922

26,528

18,238

18,238

 16,580

21,554

19,896

23,212

18,238
Sect. #11

Sect. #12

Sect. #13

Sect. #14

Sect. #15

 12,435

17,409

11,606

12,435

9,948

 14,922

24,870

15,751

10,777

10,777

 17,409

17,409

10,777

12,435

11,606

 14,922

29,844

23,212

10,777

12,435

 28,186

41,450

22,383

12,435

10,777

 21,554

28,186

16,580

11,606

14,922

 26,528

24,870

15,751

12,435

11,606

 25,699

31,502

19,607

9,948

8,209
Sect. #16

Sect. #17

Sect. #18

Sect. #19

Sect. #20

 14,922

24,041

24,870

18,186

37,305

 19,896

22,383

23,212

27,357

29,015

 23,212

31,502

18,238

23,212

15,751

 16,580

26,528

24,041

36,476

24,041

 17,409

30,673

29,844

26,528

28,186

 16,580

36,476

24,870

32,331

30,673

 15,751

28,186

37,305

34,818

30,673

 18,238

20,725

16,580

31,502

26,528
Sect. #21

Sect. #22

Sect. #23

Sect. #24

Sect. #25

 41,450

18,238

42,279

26,528

21,554

 25,699

29,015

38,134

26,528

19,896

 20,725

32,331

19,896

22,383

26,528

 27,537

29,844

24,870

16,580

16,580

 21,554

23,212

41,450

22,383

24,870

 38,963

21,554

24,041

33,160

25,699

 26,528

23,212

24,041

28,186

28,186

 29,844

16,580

25,699

34,818

29,844
Sect. #26

Sect. #27

Sect. #28

Sect. #29

Sect. #30

 24,870

29,844

31,502

31,502

29,015

 16,580

33,160

29,015

24,870

24,041

 20,725

36,476

34,818

28,186

28,186

 21,554

34,818

30,673

28,186

29,015

 26,528

34,818

33,989

22,383

24,870

 20,725

25,699

34,818

31,502

24,870

 26,528

36,476

39,792

30,673

31,502

 19,067

30,673

32,331

32,331

31,502
Sect. #31

Sect. #32

Sect. #33

Sect. #34

Sect. #35

 29,844

33,160

56,372

33,989

39,792

 38,134

29,015

49,740

29,015

35,647

 49,740

38,134

56,372

34,818

34,818

 41,450

39,792

44,766

38,134

41,450

 34,818

33,160

41,450

34,818

46,424

 43,108

36,476

38,134

38,134

49,740

 48,082

33,160

39,792

33,160

43,108

 41,450

31,502

40,621

31,502

41,450
Sect. #36

Sect. #37

Sect. #38

Sect. #39

Sect. #40

Sect. #41

Sect. #42

Sect. #43

 40,621

49,740

50,569

44,766

53,056

54,714

57,201

58,030

 40,621

43,937

46,424

43,937

57,201

49,740

58,030

 38,134

41,450

46,424

42,279

57,201

58,030

 46,424

51,398

58,030

56,372

58,030

 41,450

56,372

58,030

 49,740

58,030

 38,134

44,766

58,030

 43,108

56,372

57,201

58,030

Chance Civil Construction
1026-B South Powell Road
Independence, MO 64056
Office: (816) 796-6800
Fax: (816) 796-0919
Toll Free: (877) 285-2739
Email: info@atlassys.com