DFMC - Structural Observation Report 01272021 v.2 (1)_0002.pdf

STRUCTURAL OBSERVATION ASSESSMENT

White Mountain Apache Tribe Detention Facility

Whiteriver, AZ

Report Date:

January 27, 2021

Assessment Date:

January 21, 2021

Prepared By:

INDIAN AFFAIRS

Office of Facilities, Property, and Safety Management

Division of Facilities Management & Construction

1011 Indian School Road, NW, Suite 335

Albuquerque, New Mexico 87104-2303

Contents

1. Background

1. Observations

1. Settlement at Door 104A

2. Joist Intersection at Non-Load-Bearing Walls

3. Interior & Exterior Cracking

4. Roof Flashing Details

5. Site Drainage

6. Rodent Activity

2. Assessment

1. Settlement at Door 104A

2. Joist Intersection at Non-Load-Bearing Walls

3. Interior & Exterior Cracking

4. Roof Flashing Details

5. Site Drainage

6. Rodent Activity

3. Recommendations

1. Infill Joist Intersections at Non-Load-Bearing Walls

2. Door 104A

3. Cracking

4. Pipe Repair

5. Rodent Control

4. Conclusions

1. Background Two previous structural assessments were performed on separate occasions and reports were provided summarizing the findings and recommendations for repairs. The first report, dated May

17, 2019, was prepared by T.H.A.T Consultants. The second report, dated December 20, 2020, was prepared by Martin White & Griffis Structural Engineers.

Prior to visiting the facility, Graham Allen from DFMC reviewed the two structural assessments, available project construction documents, and the original soils report. The observations in the two prior assessments are through and well documented and will largely not be duplicated in this assessment. However, differences in the recommendations outlined in the two reports warranted the visit by DFMC to determine the best course of action for repair.

1. Observations

1. Settlement at Door 104A

Apparent settling of the footing under the column adjacent to the door frame has caused vertical cracking on the interior walls and spalling of the CMU face shells on the exterior. With several of the face shells missing, the steel column within the CMU is exposed in several places. The photos below document the current condition of this area.

2. Joist Intersection at Non-Load-Bearing Walls

At the upper level roof where the steel roof joists pass through non-load-bearing masonry walls, there are several instances of the infill material cracking and becoming loose. The photos below document this condition.

3. Interior & Exterior Cracking

Cracking of the CMU walls, the slab on grade, and the roof between the first and second story was visible in many locations. The photos below show the typical types of cracking that were encountered throughout the building.

4. Roof Flashing Details

The cap flashing along the lower roof parapet at the intersection with the second story walls has separated leaving a gap allowing for water infiltration. Several repair attempts have been made to caulk this joint. This detail is found at both the north and south elevations. The south elevation instance occurs in plane with the exposed column at

Door 104A.

5. Site Drainage

Erosion was noted around the splash pads at the downspouts creating the opportunity for ponding near the foundation. The area inside the electric yard was visibly saturated, which is apparently due to water discharging from the malfunctioning boilers. At the time of observation, these systems were scheduled to be replaced in the near future.

6. Rodent Activity

There is evidence of rodent activity around the perimeter of the building and inside a plumbing chase access within the building. The photo below on the left shows activity around the vertical pipe penetration through the slab on grade. The photo on the right shows the activity near the foundation.

2. Assessment

1. Settlement at Door 104A

The settlement of this area appears to be localized to only this location. As mentioned in the previous structural reports, this condition is not believed to be the result of a flaw in the building design. The report from MWG stated that water infiltration and/or poor soils are common causes of foundation settlement. However, the report did not identify a source of water infiltration. It is possible that the source of the water infiltration could be from the unsatisfactory flashing detail at the parapet above. Water has the potential to enter the wall cavity from above and move towards the foundation below. At the time of observation, the roof was being replaced with a membrane roof and a more appropriate detail was being implemented as shown in the photos in Section 4.

2. Joist Intersection at Non-Load-Bearing Walls

According to the construction documents (RE: Detail 230/S501), the voids in the masonry wall were to be filled with a “compressible material.” It appears that the voids were filled with typical masonry grouting material that does not meet this design requirement. Normal building movement and deflection of the roof joists is causing this material to crack and become loose, in some areas the material has fallen off. While this condition is not considered structurally unsafe, falling debris can become a potential hazard to occupants.

3. Interior & Exterior Cracking

The observed cracks in the building are not of significant structural concern at this time and are considered common in buildings constructed with masonry materials.

4. Roof Flashing Details

The existing flashing detail does not allow for structure movement and creates an opportunity for water infiltration into the wall cavity. This is apparent in the repair attempts to re-caulk the joint. The new roofing detail currently being installed should perform better at these locations.

5. Site Drainage

The original soils report by Terrane Engineering Corporation, dated August 29,2005, recommends that positive drainage away from the building be maintained with an outfall of 2 percent for a minimum of 10 feet. Soft wet soils observed around the foundation indicate that this requirement may not be met by the current drainage system(s). Erosion at the ends of the splash pads under the downspouts creates the potential for ponding closer than 10 feet to the building. Drains from the current boiler system also appear to be depositing water immediately next to the foundation.

6. Rodent Activity

The rodent activity does not appear to be the cause of any structural damage. However, burrows near the foundation can create the potential for water infiltration under the building foundation.

3. Recommendations The following repair recommendations are listed in order of importance and urgency.

1. Infill Joist Intersections at Non-Load-Bearing Walls

While not a structural concern, this repair can be performed to allow the unoccupied areas to be put back into use. At the time of DFMC’s visit, at least one block was unoccupied due to concerns of falling debris. The masonry grout material should be removed and replaced with a compressible material in accordance with the original specifications.

2. Door 104A

To repair this area, it is first recommended that the cause of the settlement be determined. If the rest of the repairs are done without addressing the underlying cause of the settlement, it is probable that the issue will continue, and future repairs will be required. To determine the cause of settlement a geotechnical engineer should be consulted to test the soils supporting the foundation to ensure they are satisfactory according to the original geotechnical report. If the geotechnical engineer concludes that supplemental foundation support methods are necessary, then those improvements should be implemented prior to continuing with other repairs. Once the foundation has been adequately supported (if deemed necessary) the CMU around the column can be repaired/replaced. Masonry cells around the column should be fully grouted in lift heights that promote adequate consolidation of the grout. Per MWG’s recommendation, veneer ties can be used to improve the connection of the face shells. The expansion joint adjacent to the column can then be cleaned and re-caulked using an appropriate product.

DFMC agrees with MWG that the repair proposed by T.H.A.T. is not necessary.

3. Cracking

Separate from re-caulking the expansion joint near Door 104A to prohibit water infiltration, the other cracks are largely cosmetic. These cracks can be tucked and pointed and repainted. At locations where the cracking is located at a joint, it is recommended that caulk be used to seal the crack as these areas will likely crack again.

All cracks should be monitored periodically for crack width growth as this can be an indication of an underlying problem.

4. Pipe Repair

During the site visit, recent scope photos of a drainpipe were presented that indicate the presence of debris in the line likely introduced during construction. While not a structural issue, this debris prevents water from draining and prohibits the use of at least one fixture. It also prevents scoping the line beyond the blockage. This debris should be removed, or the pipe section replaced, and further scoping should be performed to ensure there are no breaks in the line that would allow for water infiltration under the slab.

5. Rodent Control

It is recommended that pest control methods be implemented to prevent or reduce further infestation immediately surrounding the building and that existing burrows be filled and positive drainage away from the foundation be restored.

4. Conclusions Based on the previous assessments performed by T.H.A.T Consultants and MWG and the conditions encountered by the DFMC representative, the facility is considered to be in operable condition. The recommendations and analysis presented in the MWG report are largely in line with the recommendations offered here. The MWG report is considered accurate and thorough based on DFMC’s assessment.