alert - warning

This page has not been translated into Español. Visit the Español page for resources in that language.

Eastern Walnut Street Bridge

Appeal Brief Appeal Letter Appeal Analysis

Appeal Brief

DesastreFEMA-1093-DR
ApplicantPennsylvania Dept. of Transportation
Appeal TypeSecond
PA ID#000-92003
PW ID#88119
Date Signed1999-04-27T04:00:00
Citation: Second Appeal by Pennsylvania Dept. of Transportation (PennDOT) for $1.7 million additional funding to cover reimbursement of the costs of reinforced concrete jackets around the stone piers of the historic Eastern Walnut Street Bridge.

Cross-Reference: Identification of damage, potential hidden damage, unreinforced masonry: FEMA Record: DSR #88119.

Summary: PennDOT claims that the failure of two bridge piers on the Western Bridge of the bridge (a separate bridge from the Eastern Bridge) is evidence that the piers on the Eastern Bridge have suffered hidden damage. PennDOT claims that this can only be corrected by wrapping the original stone piers in reinforced concrete jackets. Based on the recommendation of PennDOT's consulting engineers, the stone piers were encased in reinforced concrete jackets. Construction has been completed. PennDOT requests an additional $1,793,785 for the work.

Issues: Can FEMA eligibility for structural upgrade work be justified on the basis of a claim that a potential for hidden damage exists when there is no physical evidence that actual damages are sufficient to justify such upgrade work? Is potential hidden damage identified as "core cracking" of significant concern when dealing with these particular unreinforced masonry piers?

Findings: The PennDOT claim that hidden damage must exist is found to be indefensible based on the scientific characteristics of unreinforced masonry piers with rubble masonry cores in general, and the lack of verifiable evidence that any of the subject piers had been structurally compromised to such an extent that they cannot be repaired only by grouting and repointing. The FEMA findings are that: (1) There is no evidence that the flood-related damage to the piers cannot be repaired by repointing and grouting of the unreinforced masonry. (2) There is no scientific basis for the claim that the failure of two piers on the Western Bridge is relevant to the claim for the cost of the concrete jackets. (3) Damage from deferred maintenance alone is not eligible. (4) Hypothetical damage that has not been documented or verified to exist is not eligible. The appeal is denied.

Rationale: FEMA Public Assistance funding is for verified actual disaster damage repair. Structural upgrading or replacement of an element done as a consequence of an assessment of the total damage to an element from age and lack of maintenance AND the impact of a particular disaster is not eligible when the repair of the disaster damage alone would not require such measures.

Appeal Letter

April 27, 1999

Charles F. Wynne
Governor's Authorized Representative
Pennsylvania Emergency Management Agency
Box 3321
Harrisburg, Pennsylvania 17105-3321

REF: Pennsylvania Dept. of Transportation, Eastern Walnut Street Bridge, FEMA-1093-DR, PA 000-92003, DSR #88119.

Dear Mr. Wynne:

This letter is in response to your letter of May 22, 1998, forwarding the second appeal of Damage Survey Report (DSR) # 88119 submitted by The Pennsylvania Department of Transportation (PennDOT) to Pennsylvania Emergency Management Agency (PEMA) on May 14, 1998. Further information for this appeal was received from the subgrantee and forwarded by you to FEMA on September 30, 1998. The appeal was forwarded to me on November 13, 1998 after the preparation of the enclosed TAC III Technical Report. The applicant has requested funds to reimburse the costs of adding reinforced concrete jackets around the existing bridge piers on the Eastern Walnut Street Bridge.

In response to this claim, FEMA has had the issues reviewed by an outside consulting engineer under its Technical Assistance Contract. The study found no basis on which to support the subgrantee's position in this appeal. As explained in the enclosed analysis and Technical Report, the PennDOT appeal is based on the possibility of damage existing that has not been observed or verified to exist. In addition, the kind of damage (namely "core cracking") on which its claim rests is not a kind of damage which is significant to the stability of unreinforced masonry piers with rubble masonry cores. FEMA has already funded the complete repair of the observed disaster damage to the subject piers in DSR 88119. Accordingly, the applicant's appeal is denied.

Please inform the applicant of this determination. In accordance with the appeal procedure governing appeal decisions made on or after May 8, 1998, my decision constitutes the final decision on this matter. The current appeal procedure was published as a final rule in the Federal Register on April 8, 1998. It amends 44 CFR 206.206.

Sincerely,
/S/
Lacy E. Suiter
Executive Associate Director
Response and Recovery Directorate

Enclosures

cc: Rita A. Calvan
Regional Director
FEMA Region III

Appeal Analysis

BACKGROUND
The Walnut Street Bridge was constructed in 1890 over the Susquehanna River in the City of Harrisburg, Pennsylvania. Distinguished by its series of steel "Baltimore Pratt" Trusses, it has been recognized as an engineering landmark, and is listed on the National Register of Historical Bridges.

The Walnut Street Bridge is actually two separate structures crossing the East and West Channels of the Susquehanna River. Each terminates at City Island, which separates the two channels of the river. Only the Eastern Bridge is the subject of this appeal.

Both sections of the bridge are composed of a series of spans resting on stone piers. Eight spans cross the West Channel, and seven spans are over the East Channel. This appeal only involves the bridge over the East Channel (Eastern Bridge). The Western Bridge remains unrestored, with three spans and two piers missing as a result of the flood. FEMA action on the West span is still in process, and not at issue in this appeal. The Eastern Bridge survived the flood intact, with all spans in place. This appeal concerns only the cost of repairing and upgrading the stone piers of the Eastern Bridge. It does not concern the steel superstructure.

THE DAMAGE
The Walnut Street Bridge was damaged during the January 1996 flood with water 20 feet above the flood stage capped with ice flows. The most conspicuous damage to the bridge was the loss of a pier and two spans of the Western Bridge. A local amateur managed to film the spans as they came off their footings and remained resting on the ice flow until they crashed into the Market Street Bridge down river. A third span and pier were heavily damaged, and, it was reported that during efforts to remove the trusses with a crane, they fell off of the pier and were destroyed.

The Eastern Bridge did not suffer such catastrophic damage. In fact, the narrative in DSR 88119 (inspection date, July 16, 1996) states that the bridge "received minimal damage in comparison to the West side.[and] in comparison to the extensive deterioration that existed prior to the disaster." The damage to the piers of the Eastern Bridge was reported in the DSR to consist only of "additional" loss of mortar from between the stones (additional to the loss that had been documented earlier in two separate pre-flood engineering surveys contracted for by the Pennsylvania Department of Transportation (PennDOT).

DSRs WRITTEN
A single DSR is under appeal: DSR #88119. This DSR is for $260,109 to cover repointing and grouting of the piers, and some minor replacement of steel members in the superstructure. The inspection date for this DSR was July 16, 1996, and it was PAPPED on January 7, 1997. (The Western Bridge is covered by separate DSRs.)

SECOND APPEAL REQUEST
The request from PennDot for the second appeal is for $1,793,785 in addition to the $260,109 already approved in DSR 88119, for a total of $2,053,894. This request is based on the reimbursement of the costs from the bridge restoration project related to the construction of reinforced concrete jackets on every pier. The single basis for the appeal is the "concern .for concealed damage to the east span piers as a result of the same horizontal loading that destroyed the two west span piers." The principle items submitted as evidence are the statements by two of the State's consulting engineers that such an encasement is necessary.

In their first appeal PennDot had requested the entire $6,019,998 estimated cost for the restoration of the bridge including the encasement of all of the stone piers. This had been denied based on the FEMA finding that the disaster damages did not justify all of the work. The second appeal asks again that FEMA consider the encasement as being required, but apportions the costs between "cost flood" and "cost rehab" in a spreadsheet entitled Eastern Walnut Street Bridge Side Construction Costs." The "rehab costs" relate mainly to the rehabilitation of the steel superstructure.

The Technical Reports that are on file and used for this appeal response include the following:
  1. December 12, 1992: Modjeski and Masters, Engineers, one-page deck Level Inspection.
  2. December 1993: Modjeski and Masters, Engineers, Inspection and Evaluation.
  3. August 1994: Collins Engineers, Underwater Investigation.
  4. February 1996: Collins Engineers, Underwater Investigation (post-flood).
  5. Undated (approx. July 1996): Modjeski and Masters, East Channel Rehabilitation.
  6. October 1998: FEMA TAC III Technical Report, East Walnut Street Bridge.
DISCUSSION
  1. The PennDOT Claim: This case rests on the issue of distinguishing between disaster damage and long term deterioration. While the Stafford Act provides funding to repair damage caused by a disaster, it does not provide funding to correct deterioration from other causes. However, this appeal raises the question of how does one distinguish between, or draw funding boundaries around, damage from a disaster to an element and other damage not from the disaster to the same element when the element has not failed, but has simply been further damaged?

    The Stafford Act does not provide for a discounting of claims based on the age or condition of an element or structure at the time of a disaster. Commonly FEMA assistance has covered the full cost of repairing a destroyed element if the actual damage or failure occurred as a result of the disaster event regardless if there were contributing causes. The situation is more complicated, however, for those elements where the disaster forces caused additional damage to an element which was already deteriorated, but where the necessary corrective work for the damage can be successfully executed separately from the repair of deterioration from other causes. In such cases, the Stafford Act will provide for funding to cover the cost only of the repair of the disaster damage alone. If some of the pre-existing deterioration is corrected as a by-product of the cost-effective repair of the actual damage, all well and good. However, the Stafford Act does not make it incumbent on FEMA to repair all existing deterioration to an element, only the disaster related damage.

    In the case of the Eastern Walnut Street Bridge, the damage involves the stone piers supporting the trusses. The PennDot claim does not distinguish between elements of damage. It simply claims that the structural upgrading of the piers (with reinforced concrete jackets) was a necessary part of the repair to predisaster condition. Its claim is based on the perceived potential instability of the piers as a consequence of all accumulated damage to them, not the disaster damage alone. PennDOT does claim, however, that the pre-disaster condition cannot be regained by repairing the visible damage caused by the disaster alone. Their claim is predicated on a theory that hidden damage must be assumed to exist because of the performance of the piers on the Western bridge which were destroyed by the flood, rather than any detected actual damage to the piers on the Eastern bridge themselves.

    PennDot cites in support of its case two engineer's reports, the Modjeski and Masters Report (M&M Report), no date - ca. July 1996, and the A.G.Lichtenstein letter, August 2, 1996). The Modjeski and Masters Report recommended the jacketing of the piers as part of the post-flood repair, and the Lichtenstein letter supported the recommendation.

    The PennDot appeal raises the following specific issues:
    1. "The Department's main concern was for concealed damage to the east span piers as a result of the same horizontal loading that destroyed the two west span piers."
    2. "A comparison of the underwerary of 1996 indicated that the flood/ice flow event did have a damaging effect on the substructure."
    3. "Review.of the failed west span piers" by Modjeski and Masters revealed that "the rubble masonry core was in very poor condition." (M & M Report, p1)
    4. "A summary of [the M&M] evaluation which states that: `Without the most recent event and the failure of the two west channel piers from the lateral loads, the pier encasement would not be required in a typical maintenance scheme.'"


    These points can be expressed as the following issues: (1) the possible hidden damage in the piers, (2) the position held by an inspecting engineer that grouting and repointing of the pier cores will not restore the pre-flood condition, and (3) the belief that the piers are "unstable under certain loading conditions" [loading conditions which have not been described], and thus require jacketing, rather than repointing and grouting for safety to be assured.

  2. FEMA TAC III Technical Findings: Prior to the forwarding of this second appeal response to FEMA Headquarters for review, Region III commissioned its Technical Assistance Contractor (TAC) study of the PennDOT claim. I.C.F. Kaiser from FEMA's TAC III conducted this study. The conclusions of this analysis were presented in a report: Technical Report, East Walnut Street Bridge, October 1998. This report responds to the same questions that are under appeal, namely whether all or part of the PennDOT costs to jacket the stone piers are required by the repair of damage and thus eligible for FEMA reimbursement.

    The main point raised by the Subgrantee is the need to address the possibility of hidden damage, and the belief that such damage could not be repaired with confidence by pressure grouting and repointing alone. In support of their case, PennDOT cites the findings and recommendations of their consulting engineers who concluded that the concrete jackets were a necessary and prudent upgrade of the piers in response to the condition the piers were in following the disaster. However, the TAC III engineer was charged with the responsibility of addressing a more limited question: were concrete jackets eligible for FEMA funding as a necessary part of the repair of the disaster damage per se?

    The TAC III analysis included a review of all of the reports cited in the appeal as evidence, as well as reviewing the FEMA record. The conclusion of this report was that the reinforced concrete jackets were not a necessary part of the disaster repair, and that the funding already authorized was basically adequate to address the repair of the disaster damages.

    This report responded to the series of questions raised by PennDOT in their appeal:
    1. The fact that the East channel piers sustained the same forces as the West channel piers leads one to conclude that hidden damage could be almost as severe as what caused the West piers #3 & 4 to fail.TAC III reports that they could find no evidence to support the conclusion that the level of damage in the eastern piers could be extrapolated from such an observation. The fact that the piers are all of the same age and design, and that all were exposed to the same flood waters, does not mean that it can be concluded, without physical evidence, that all those which survived the flood must have come close to collapsing.
    2. Re-pointing and injection grouting will not insure the pier is repaired to its pre-flood condition.TAC III engineers disagree with this positions, stating that "Pressure grouting will likely fill the voids within the piers to a state equal -to or better than the condition of the cores prior to the flood."
    3. The piers are unstable under certain loading conditions.TAC III found no evidence that the piers had been leaning or tilting prior to the work, or that any re-leveling had been done in connection with the work. There was some evidence of undermining, but the repair of this damage is not at issue because it had been included in the approved DSR.

  3. The Hidden Damage Issue: PennDOT defends the need for the reinforced concrete jackets by citing the loss of the spans on the Western Bridge as evidence.All the piers in the river experienced the same ice and water loads and forces which caused the failure and loss of 2 piers and three spans of [the] bridge. As these piers experienced the same forces, we would have to make the assumption that all piers have received damage that is not visible or detectable. (Memorandum from Rodney Keefer, PE, PennDOT to John Connolly, FEMA, June 13, 1996, in DSR#88119)
    Fortunately, a local citizen caught the failure of the two sections in the Western Bridge on videotape. This videotape documents the dramatic final ride the two spans took as they floated on the ice pack down river, only to be folded up and sunk upon impact with the bridge down river. This videotape is significant in this case because the PennDOT argument is predicated on the point that the Eastern Bridge's piers must have suffered hidden damage to the point of near collapse because the same ice flows caused the partial collapse of piers 3 & 4 on the Western Bridge. The videotape tells another story.

    Two spans were carried away by the flood. The third span, which was subsequently removed, was still standing on its pier after the flood had receded, but the pier and span were badly damaged. The videotape documents that dramatic final ride that the two lost spans took down river, after they were knocked off of the piers by the ice flow.

    The videotape evidence supports a finding that the spans were shoved onto the ice by a pileup of ice upstream. The photographs in the March 27, 1996 Collins Engineers inspection report show that piers #3 and #4 remained standing after the flood, but they were slightly tilted at an angle lengthwise. The underwater analysis in the report states that they had been shifted down river because of a shear failure at their bases.

    While PennDOT claims that the loading on the piers by the ice caused the failure, and that loading must have been the same for all piers, the videotape clearly shows that the broken ice pack moving on top of the flood waters was concentrated under the spans which failed. The claim that all piers were subjected to the same ice flows is thus refuted by this observable fact in the videotape.

    Despite the fact that piers #3 and #4 were both shifted off their bases at the time that the spans went down river, they remained standing for the duration of the flood. This was even the case for pier #3, which no longer had the benefit of the spans to hold its top in place. This condition points to the likelihood that the failure was caused by the pressure of the ice flow on both the piers AND the bridge decks. Had it been on the piers themselves, it would have been likely, once the bridge decks were lost, that pier #3 would have continued to be shifted downstream or toppled over.

    There is a point where the pileup of ice under these two spans most likely simply overwhelmed the strength of the bridge to resist it. Unreinforced masonry, not being a ductile system, will simply give way if the force is large enough. Ice of that thickness pressing against the bridge decks can deliver a force that the bridge was never designed to withstand. It does not follow from this fact that undetectable damage to any of the other piers must exist.

  4. Unreinforced masonry pier performance: The historic piers of the Walnut Street Bridge are of unreinforced masonry construction. They are constructed of large granite blocks with a stone rubble and mortar fill. The long term survival of bridges dating back even to Roman times proves that unreinforced masonry is a snt lcause the dead weight of the masonry itself together with that of the bridge superstructure above it serves to maintain the lines of force vertically through the structure to the ground.

    One of the important attributes of unreinforced masonry is that it can be repaired repeatedly. As long as the individual masonry units (in this case, the large stone blocks) remain sound and close to their original dimensions, the masonry structure can usually be maintained and repaired by repeated renewal of the bedding mortar by repointing. In the case of solid masonry structures with filled cores, such as the Walnut Street Bridge piers, the interior cores must also be maintained in a firm and solid condition. This condition is usually maintained by periodic grouting.

    In the case of bridge piers of the Walnut Street Bridge design, the lack of steel reinforcement should not be seen as a disadvantage. One of the significant advantages of unreinforced masonry for bridge construction is that there is no internal metal that is prone to oxidation in the wet environment. The rusting of steel can quickly serve to break up a structure in which it is located, and repairs are extremely difficult to accomplish without reconstruction. By contrast, the reinforced concrete jackets have the disadvantage of making future repairs much more difficult to accomplish. When the reinforcing begins to rust, as inevitably it will, cracks will be opened in the concrete, leading to further deterioration. Such deterioration is very difficult to repair, and future removal and replacement of the jackets is almost impossible to do. By adding the reinforced concrete jackets, PennDOT has moved from a structural system which, with proper maintenance, can last hundreds of years to one that cannot.

    There is no evidence that the piers on the West span failed only because of the lateral loads placed on them. There is no documentation of any significant cracking, shifting, or dislocation that would indicate instability or near failure of any of the remaining piers. If there were, PennDOT would not have to rely on the weak argument that damage that is "not visible or detectable" exists.

    The June 13, 1996, PennDOT memorandum criticizes the FEMA DSR 488119 scope by stating:
    "How does FEMA address the potential for core cracking from the ice forces? How does FEMA ensure pier stabilization? Intrusion grout and pressure pointing will not be effective on the overturning forces generated with potential core cracking that produces resistance to overturning." [sic: it is likely "reduces" rather than "produces" was intended.]
    In response to this comment, it is important to point out that unreinforced masonry piers do not resist overturning because of any monolithic integrity of their cores. There simply is no such thing as an "uncracked" core in unreinforced masonry structures because they are simply not designed to resist forces in tension. The core material is not a homogeneous and solid mass of material. It is a heterogeneous mixture of stone, mortar and hydraulic grout or cement. The existence of cracks in the material is irrelevant because all masonry is, by definition, discontinuous. Masonry structures gain their resistance to tension or overturning forces simply by the weight of the overburden that keeps them in compression even when lateral forces are applied.

    It is large voids, not cracks, which are to be avoided in masonry pier cores. Since pressure grouting seeks out and fills voids very easily and predictably, such a repair technique is eminently suitable for the proper repair of a damaged pier. Grouting and repointing of the piers already has been determined eligible by FEMA for the bridge repair.

    PennDOT raises the criticism that the results of pressure grouting cannot be inspected without dismantling the pier to see if the voids had been filled. This is unnecessary. The grouting of rubble-core masonry structures is not an experimental process. It is a time honored and accepted process used in conservation and restoration worldwide. The objective is not to penetrate every crack or fill every crack or void that may exist within a core, but to consolidate the core by filling the significant voids that have resulted from deterioration, compaction or erosion. Pressure grouting is very easily able to accomplish this when executed in the proper way.


As the FEMA TAC III Report states, the evidence is that the lost piers failed because pre-flood deterioration caused them to be vulnerable to progressive and rapid loss of stability because the floodwaters were able to penetrate into the rubble cores. (As observed above, any such failure, even if it did occur, followed the loss of the bridge spans, which had been forced off by the ice first.) When moving water does penetrate into the core under the pressure of the flood it can cause a rapid loss of the inner core material, leading to instability. In instances where this condition occurs, there is little to prevent the shifting or collapse of the pier, or if the pier remained standing, the hollowed out core and dislodged stones would be relatively easy to detect by inspection.

It can thus be concluded that in those instances where the piers survived without being visibly shifted, dislodged or significantly hollowed out, this condition did not occur. Such piers are repairable with the use of grout and repointing without the need for externally applied reinforcement. There is no reason that proper restoration with pressure grout and repointing cannot restore any lost capacity to a level close to that of the original construction. This is true so long as the external blocks of stone are themselves still in sound condition and the stone structures have not been shifted or dislocated. The Eastern Walnut Street Bridge piers meet these criteria.

CONCLUSION

PennDOT has appealed for an additional $1,793,785 to cover the cost of the installation of the reinforced concrete jackets. FEMA has already approved $260,109 to cover the costs of grouting and repointing, etc. The jackets have been completed.

For the reasons documented and explained above, FEMA has concluded that the reinforced concrete jackets installed by PennDOT were not required as a consequence of the declared disaster event, and are thus ineligible for FEMA assistance. FEMA's consulting engineer's conclusions are also contrary to the PennDOT position, as shown above.

The Eastern Bridge pier structures were originally constructed of unreinforced masonry, and they remained stable after over 100 years of exposure to floods, despite the many years of inadequate maintenance or repair. The PennDOT argument that they are potentially unstable because of "invisible" damage or "core cracking" is simply not credible for the reasons stated above.

The potential for hidden damage is frequently raised in Public Assistance cases, more often in connection with earthquake damage. The FEMA Public Assistance Program, as authorized by the Stafford Act, provides funding for the repair of damages. It is not intended to provide assistance for the repair of hypothetical damages, only actual damages. It is the subgrantee's responsibility to find and verify disaster-related damages. In the case of the Eastern Walnut Street Bridge, the PennDOT claim for funding of the structural redesign of the piers rests on the (misinterpreted) performance of two out of seven piers on another bridge which failed. It does not rest on any verified damage to the subject piers which would indicate the lack of stability or resistance to overturning on which the appeal is based. This second appeal is denied.