Motorists on the 5- 14 interchange, just north of the epicenter of the Northridge earthquake, got an uncomfortably close-up view of the severity of the quake's damage.
The world didn't come to an end last January 17th. But for about 30 seconds in Los Angeles, it sure seemed like it. At 4:31 a.m., a forgotten earthquake fault awoke from a long slumber, triggering the most devastating seismic event in Los Angeles history.
The 6.8 magnitude Northridge earthquake was blamed for some 60 deaths, thousands of injuries and billions in property damage. But nowhere was the destructive power of nature more evident than in the collapsed sections of four major freeways, including the nation's busiest, Interstate 10, and California's lifeline of commerce, Interstate 5. For an estimated 1 million commuters, getting around L.A. would not be the same for a long time.
The Northridge earthquake posed one of the greatest challenges to the California Department of Transportation in its nearly 100-year history. It also proved to be one of its greatest triumphs, testing the mettle and ingenuity of Caltrans employees in ways no one could have possibly foreseen. In an era of shrinking government budgets and eroding confidence in the public sector, Caltrans and the many other agencies involved rallied to the cause of earthquake recovery. It was this single-minded determination, along with some sound project management, that resulted in freeways being rebuilt in a fraction of the time originally predicted, with high quality and at a reasonable price. As Governor Pete Wilson put it recently, this is the story of the great “California Comeback.”
Caltrans and the many other agencies involved rallied to the cause of Earthquake recovery. It was this single-minded determination, along with some sound project management, that resulted in freewags being rebuilt in a fraction of the time originally predicted.
CALTRANS AND FREEWAYS
Aside from its beaches and ubiquitous palm trees, perhaps the most prominent feature of the Los Angeles area is its freeway network. There are 27 freeways totaling 615 miles within District 7, and the system was built around the concept that the automobile held the future of our mobility and that everyone should live within a few miles of a freeway. Each day, the freeways accommodate 102 million vehicle-miles of travel, or the equivalent of more than 200 round trips to the moon.
Designing, building and maintaining this vast transportation grid is the responsibility of the California Department of Transportation, popularly known as Caltrans. It was established by the state legislature in 1972 and grew out of the former state Department of Public Works, Division of Highways. Other Caltrans responsibilities include mass transit system enhancement, railroad system development, seaport and waterway expansion, air transportation planning and assisting area governments and agencies in planning and developing local transportation improvements. Cal-trans is divided into 12 regional districts. District 7, which includes Los Angeles and Ventura counties, is the second largest of these districts and serves a population fast approaching 10 million. District 7 employs approximately 2,800 people, with the largest group-l,345-working in the Construction and Maintenance area. The District's Design Department has 491 employees and the Traffic Operations Department employs 325. The annual support budget is $162 million for personnel and $101 million for operations. During the next seven years, the District will manage a budget of approximately $2.3 billion, which includes all aspects of highway and inter-city rail design and construction.
THE EARTHQUAKE
L.A. is often described as many small communities searching for a center. It is the freeway system that connects it all together. Several of those connections were broken on January 17, 1994. The ground shook for about 30 seconds, and seismologists later put the quake's magnitude at 6.8 on the Richter scale. Even though it was not the much feared magnitude 8 earthquake expected to strike the San Andreas fault that runs up the spine of California, the Northridge quake nevertheless caused terrific shaking in the heavily populated San Fernando Valley. Seismologists later said the fault snapped in a spot nine miles below ground, and caused a violent vertical thrust on the surface of up to 12 feet. But, as those familiar with earthquakes have come to learn, the damage can be maddeningly capricious in where it strikes. For example, the Ventura Freeway, U.S. 101, which cuts through the heart of the San Fernando Valley, was barely damaged and remained in service after the quake. But just to the north on the Simi Valley Freeway (Route 118), the 566-foot-long bridge at San Fernando Mission Boulevard/Gothic Street collapsed when its ten concrete support columns gave way under intense shaking.
Stiff columns and not enough capacity on the expansion joints also were to blame 23 miles north of downtown on Interstate 5 at Gavin Canyon, where the northbound and southbound bridge decks collapsed. Just three miles to the south, bridge failures also occurred on the Antelope Valley Freeway (Route 14).
For many, however, L.A.'s quake devastation was exemplified by the Santa Monica Freeway; Concrete columns beneath the La Cienega and Fairfax bridges exploded, reinforcing steel bars 1-3/4 inches in diameter (about the thickness of your wrist) twisted out of shape like so much overcooked spaghetti, and the bridges tumbled earthward. The nation's busiest freeway, which before the quake carried up to 341,000 vehicles a day, was suddenly, savagely taken out of service.
THREE-PRONGED ATTACK
Caltrans didn't have time to stand around and mourn this potentially crippling damage to the freeway system. L.A. is car-dependent, and motorists don't tolerate even the slightest delay or inconvenience.
The Caltrans strategy of attack was on three fronts: First, there was the initial emergency response, followed by an interim traffic management strategy, and then longer-term rebuilding efforts. Each step was designed to ensure the quickest route to returning the transportation system to the way it was before the earthquake with the least amount of inconvenience to drivers. The process can be likened to how the wounded are attended to in wartime. First there is the basic triage in the field, then interim treatment at a Mobile Army Surgical Hospital (M.A.S.H.), and then finally off to a regular hospital for long-term care and rehabilitation.
In the hours after the quake, most of Caltrans' 1,000 maintenance personnel fanned out to do visual inspections of the freeway system and to initiate closures on freeways that were collapsed or considered unsafe. These initial “windshield” inspections were followed up by more detailed inspections by structural engineers. Meanwhile, Maintenance personnel, in coordination with the downtown Traffic Management Center, spent a grueling first day establishing detours around the closed freeways. This was no small feat, as information kept changing constantly. Strong aftershocks also complicated matters, forcing engineers to re-inspect bridges for signs of new damage. For the closed section of the Santa Monica (Interstate 10) and Simi Valley Freeway (Route 118), acceptable detours were available. Each area had surface city streets that paralleled the freeway. In fact, many motorists were already using these alternate routes before official detours were established.
In the case of the Santa Monica Freeway, mobility was helped by two important factors. The opening last year of the new Interstate 105 gave commuters another east-west freeway alternative to Interstate 10. Also, the Santa Monica Freeway is part of a traffic management demonstration project called the “Smart Corridor,” which links the freeway and key surface streets—primarily Olympic, Pico, Washington and Adams boulevards—to better balance traffic flows on all corridor facilities. With Interstate 10 out of service, the Los Angeles City Department of Transportation's Automated Traffic Surveillance and Control (ATSAC) was able to adjust the timing on the surface-street traffic signals to accommodate the heavier traffic diverted from the freeway. Cal-trans also employed other traffic management techniques, including the use of closed circuit television cameras to identify trouble spots, and stationary changeable message signs to relay the latest road information to motorists.
Reconstruction of the 5-14 interchange at about the halfway point.
The Traffic Management Center disseminated freeway and highway closures and suggested alternates several times a day via fax and through L.A. Cityview Channel 35, the city's government cable access channel that is available in 500,000 households. Through the use of “Freeway Vision,” viewers receive a version of Caltrans' real-time, computerized map of the freeway system that employs color-coded lights that display the latest traffic conditions. And as always, the Traffic Management Center worked closely with the news media, particularly radio traffic reporters, to help guide motorists around the closures.
It was a different story on Interstate 5, however. Truckers and commuters driving in from bedroom communities in the Antelope Valley to the north of the damage soon found there were no good alternates. Some truckers ended up taking a 40-mile inland route to get to metropolitan Los Angeles. A truck heading to Los Angeles from Bakers-field, for example, was forced to take State Route 58 east to Interstate 395 south to Interstate 15 south to Interstate 10 westbound. Truckers also took the coastal route to Los Angeles, employing U.S. 101 to get into the San Fernando Valley. Faced with hours of delay, many postponed or canceled their trips. For a state struggling to pull out of the worst economic downturn since the Great Depression, everyone at Caltrans knew it was essential to get L.A. moving again.
DEMOLITION AND DETOURS
Caltrans immediately went to work demolishing and removing the damaged structures, and then creating a temporary detour. At the I-5/Route 14 interchange, Granite Construction Co. of Watsonville, California, brought in 40 people, working around the clock, to remove about 5,000 yards of concrete and steel using trucks, loaders and pavement breakers. When the bridge resisted traditional demolition efforts, explosives were brought in and sections were blown up. Meanwhile, just to the north on Interstate 5 at Gavin Canyon, Penhall International Co. of Anaheim, California,, brought in 50 people to remove 15,000 cubic yards of concrete and steel.
At the same time, Caltrans maintenance forces, working alongside Chumo Construction of Baldwin Park, California, carved out a detour for Interstate 5 using a nearly forgotten frontage road called, appropriately, The Old Road. About 75 people worked around the clock to resurface the road with 20,000 tons of asphalt concrete, add signs, re-stripe and add K-rail. In just 11 days after the earthquake, the $3.2 million detour around Interstate 5 opened to traffic, with a capacity of roughly 50 percent of the freeway. At about the same time, another important detour opened: two lanes of Route 14 opened for southbound traffic connecting to the southbound Interstate 5. Caltrans forces re-striped the southbound truck bypass to provide one mixed-flow lane and one High Occupancy Vehicle (HOV) lane. A few days later, a detour was created for the Santa Monica Freeway using the La Cienega and Fairfax on- and off-ramps for car-pools of two or more. The detour cut delay time to about 3 to 4 minutes for HOV traffic, and 18 to 20 minutes for mixed-flow traffic.
An altogether different detour was put in place for the Simi Valley Freeway. The eastbound bridges had collapsed at San Fernando Mission Boulevard/Gothic Street, but the westbound bridges had just sagged. A $3.8 million contract was awarded to shore-up the former westbound bridges, re-pave to a smooth surface, and re-stripe the freeway to allow that structure to carry three lanes in each direction. The detour was completed February 20.
REBUILDING
Once the major detours were in place, traffic started to return to near normal levels. At the same time, rider-ship on transit services, which experienced a sharp spike immediately after the earthquake, headed back toward pre-quake levels. The most visible of the transit options was the new Metrolink commuter rail service. The Santa Clarita line, which carries Antelope Valley commuters into downtown, had a ridership of more than 21,000 passengers per day one week after the quake, but recently has been carrying less than 3,000 passengers a day. Ridership on special express bus service created after the quake has been light. However, a recent Metrolink survey found that half of the riders had started riding the train since the Northridge earthquake, and many of those cited quake damage as the reason they were no longer driving to work.
Although there were initial estimates that it would take two years or more to restore the freeways to prequake service, all quake rebuilding jobs are scheduled to be completed by the end of this year.
That's not to say that transit wasn't important after the quake. Expanding bus service and the rapid opening of new Metrolink stations gave thousands of Angelenos important options for getting to and from work. There was also resurgent interest in telecommuting—working from home or a satellite location through the use of computers, fax machines, modems and telephone lines. But the statistics show that given options, a vast majority of commuters prefer their own automo-bile-on their own freeway-to other ways of getting around.
Meanwhile, Caltrans turned its attention to reconstruction of the freeways. Normally the process of awarding a contract to build a major structure takes many weeks. A contract is advertised and prospective contractors pick up bid packages and submit their proposals. At a scheduled date, the bids are opened and the lowest qualified bidder is selected for the job. Then a process of reviewing the winning bid, and finally approving it, takes place. But normal rules were thrown out the window for the Northridge earthquake. Governor Pete Wilson signed an Emergency Declaration allowing Caltrans to streamline its contracting procedures.
Another important feature of the contracts was the incentive/disincentive. If the winning contractor finished the job early, a bonus was awarded for each day that the deadline was beaten. Conversely, for every day over the deadline, the contractor would be penalized the same amount. The amount varied depending upon the importance of the route. This proved to be a powerful motivation for contractors working on the job.
On January 29, a $14.8 million contract to rebuild the Gavin Canyon bridges on Interstate 5 was awarded to E.L. Yeager Inc., of Riverside, California, and the firm was given 130 calendar days to complete the work. The incentive/disincentive was $150,000 per day. The contractor finished the job 33 days early, earning a bonus of $4.95 million.
The incentive/disincentive clause created a stir on the Santa Monica Freeway, when contractor C.C. Myers Inc., of Rancho Cordova, California, pulled out all the stops to complete the reconstruction of the Interstate 10 bridges in a blistering 66 days-or a whopping 74 days ahead of the original contract, earning a $14.8 million bonus. Myers took every opportunity to save time and streamline his operation. He greatly expanded his work force. For example, he had 228 carpenters, laborers and equipment operators on the job, when normally he would only have about 65. This job employed 134 ironworkers, when it typically would employ only about 15. These dedicated people worked around the clock, even in the rain. The work was scheduled much like an assembly line. In that way, critical activities were followed by the next critical activity. Carpenters and ironworkers acted like teams competing against each other to see who could finish first.
Crews worked around the clock to rebuild the 5/14 interchange. Shown here, a welder puts the finishing touches on the re-bar skeleton on one of many support columns.
Although Clint Myers received a substantial bonus for finishing early, he spent a lot of money on overtime, bonuses and other premiums to keep the job rolling along. Complicating matters was the fact that beneath the freeway Caltrans had leased the airspace to a storage company, and many of the storage units were crushed by the collapse of the freeway. Needless to say, the owners of the belongings stored in now flattened storage units were clamoring for compensation. Also demanding attention were many residents who live alongside the freeway. With reconstruction work going on 24 hours a day, including jack-hammering and pile-driving, Caltrans temporarily housed many families in local motels. The agency even erected a temporary plastic soundwall to help reduce the construction noise traveling to a nearby apartment complex. The double-layer curtain, 450 feet long by 20 feet high, was designed to reduce construction noise by 10 decibels.
Despite the difficulties and expense incurred by around-the-clock freeway building, most of Los Angeles cheered the Caltrans quake recovery efforts. The business community, too, was appreciative of the speed at which the Santa Monica Freeway took shape. And with good reason. The Governor's Office of Planning and Research released a report concluding that for every day the Santa Monica Freeway was closed, it cost the local economy more than $1 million. Damage to the infrastructure, the report noted, causes what economists refer to as “deadweight loss”; that is, not a transfer from one party to another, but a loss to all society. Particularly hurt was the trucking industry-4 percent of the Santa Monica Freeway traffic is trucks carrying merchandise.
PROJECT MANAGEMENT
Although there were initial estimates that it would take two years or more to restore the freeways to prequake service, all quake rebuilding jobs are scheduled to be completed by the end of this year. This was made possible because all resources of Caltrans and the Federal Highway Administration were made available to respond to this disaster. And FHWA officials were working side-by-side with Caltrans people to expedite the review process. Several other PM techniques were used to perform the restoration work in record time, as discussed below.
“Force Account” Contracts
This is a standard Caltrans tool available to respond to emergencies and disasters. It allows the immediate selection of a single contractor who is available, capable and has resources to do certain work. The contractor begins immediately, with a minimum of plans, under the direction of a Caltrans Resident Engineer, and is paid for actual labor, equipment and material costs plus overhead and profit. About 60 individual Force Account contracts totaling $20 million were awarded for such work as shoring salvageable bridges, demolishing damaged bridges and constructing detours. Contractors were at work demolishing the most severely damaged freeway bridges within hours of the Northridge quake-often with little more than a handshake and a signature on a piece of paper.
Informal Bid Contracts
Immediately after the earthquake, Governor Pete Wilson issued an Executive Order relaxing certain statutory requirements of the State Contact Act, allowing Caltrans to speed the process of designing, advertising, awarding and beginning construction contracts. With this action, Caltrans was able to advertise with minimum plans, ask for bids within three to four days, open bids and award contracts the same day and begin work the next day. This cut a normal four-month process to five days, but retained the advantage of competitive bidding. Sixty contracts of this type, totaling about $230 million, are being used to rebuild destroyed bridges, strengthen damaged bridges, and repave and repair buckled pavement and bridge approaches.
Incentive/Disincentive Contracts
In order to ensure early completion and opening to traffic of the critical, closed freeways, several informal bid contracts utilized an “A-plus-B” bid process and incentive/disincentives. An incentive/disincentive amount was determined, based on the daily cost of traffic disruption and detouring; and a maximum number of calendar days, working 24 hours a day, seven days a week, was determined. A pre-selected list of well-qualified contractors, usually five, were then asked to bid on an “A” amount for the normal contract quantities and a “B” amount based on a number of days they bid to complete the work, times the incentive/disincentive amount. The total of A-plus-B then became the basis for comparison of bids and award to the low bidder. If the contractor finished the work before the bid calendar days expired, a bonus was paid. If the contractor finished after the date, the contractor paid a penalty for each day after the deadline.
As of this writing, all incentive/disincentive contracts have resulted in early completions and bonuses for the contractors. While the $14.8 million bonus earned by the contractor on the Santa Monica Freeway, and the $4.95 million bonus earned by the Interstate 5 contractor made headlines, other major projects returned much more modest bonuses and still achieved their objective of returning the freeway facilities to the motorists in the minimum possible time.
Immediately after the earthquake, Governor Pete Wilson relaxed the State Contact Act, allowing Caltrans to speed the process of designing, advertising, awarding and beginning construction contracts. This cut a normal four-month process to five day.
Special PM Processes
Program, project and construction management for disaster response is provided by Caltrans staff personnel in much the same manner as with normal projects. In the case of the Northridge earthquake, an overall program manager is responsible for total coordination of projects. Individual project managers are responsible for delivery of plans, specifications and estimates to the point of being ready to advertise for bids. Because of the critical traffic management involved in the multiple projects under construction at one time, a detour manager was designated to coordinate the flow of traffic through and around the work areas.
Immediately after the earthquake, Business, Transportation and Housing Agency Secretary Dean Dunphy was put in charge of an earthquake recovery task force that included top decision-makers in government, including Federal Highway Administrator Rodney Slater and Los Angeles Mayor Richard Riordan. The object of the task force was to remove roadblocks to quake recovery. Quake recovery proposals were brought to the task force for review and approval the same day. If an agency was not cooperating, there was a top person on the task force to resolve the conflict.
Within Caltrans, reporting to the district director, are division chiefs in charge of traffic, design, construction, maintenance, administration, right-of-way, etc. Each was responsible for deploying resources to accommodate earthquake recovery needs.
Financial Tracking
In the event of emergencies, Caltrans Director James W. van Loben Sels has the authority to release $4 million for emergency demolition contracts. Following the declaration of a state of emergency by President Bill Clinton, an additional $100 million was made available for demolition and reconstruction from the federal highway find. Eventually, Congress voted to authorize $1.4 billion for quake recovery, which included a $200 million contingency. For the first 180 days after the quake, federal Emergency Restoration (ER) funds paid for 100 percent of the completed restoration work. Thereafter, the normal federal participating share was available.
An important part of keeping track of costs associated with the Northridge earthquake was the establishment of special Expenditure Authorization numbers for each quake contract. The E.A.'s are six digits and are similar to an account number. The first five numbers are unique to the project, and the sixth number indicates the phase of the contract. If the last number is a 1, for example, that means the contract is in the design phase, while a 4 would mean the project is under construction. Employees, too, were assigned a specific Northridge earthquake E.A. to charge their time and overtime.
Caltrans was faced with not only the problem of restoring the freeway system, but of accommodating and detouring an enormous traffic flow. Shown here is the Old Road detour below the Gavin Canyon Bridge.
Quality Control
Although design and construction of these earthquake recovery projects are proceeding at a greatly accelerated pace, quality control remains high. Partial plans, sufficient for bidding purposes, were followed with more detailed plans as the work proceeded. Timing for delivery of additional plans was committed to in the bidding documents so that contractors could plan accordingly. The contractors' 24-hour-a-day, seven-day-a-week operations, with no days off for inclement weather, were matched by shifts of Caltrans' inspectors, surveyors and material testing personnel. Projects were “partnered” between Caltrans and the contractor, greatly facilitating the progress of the work, problem-solving and quick decisions right on the job site. Contractor performance has been universally outstanding.
Minority Participation
Immediately after the earthquake, some in Los Angeles worried that in the rush to rebuild the freeways, minority- and women-owned construction firms would be left on the sidelines. To make sure that did not happen, Cal-trans set a goal that 20 percent of the quake work would go to Disadvantaged Business Enterprises (DBEs), but later upped that to 40 percent. To date, 39 percent of contracts have gone to minority- or women-owned companies, which is the highest DBE attainment in the entire state. By comparison, the model Century Freeway project hit only about 30 percent, while typical contracts usually reach 15 percent. A contract manager was responsible for tracking D/WBE usage.
Use of A&E Consultants
Much of the actual structure and roadway design, construction and engineering and contract administration was done by Caltrans' staff. However, to supplement Caltrans forces in the areas of structure design, surveying, materials testing and design of traffic management systems, consultants were retained. The governor's order allowed Caltrans to go to sole-source selection, rather than competitive bidding. Contractors were selected based on professionalism, competency and reliability, as well as previous experience, expertise, availability and proximity of resources and ability to fulfill MBE/WBE requirements. A total of 15 A&E contracts were awarded.
Key Decision-makers
Early on, Caltrans made a policy decision that once a repaired roadway was reopened, it was going to stay open. This was decided upon to avoid confusing motorists and to restore confidence in the safety of the transportation system. But this posed some logistical problems for our construction engineers. Key to resolving these conflicts was bringing in two experts from our Sacramento headquarters with experience in handling traffic detours and construction phasing. They were able to coordinate with all the contractors to make sure there were no disruptive road closures or conflicts between construction contracts. When it comes to opening or closing a freeway, all the decisions are major ones and had to be handled quickly on site.
Delegation of Authority
Because of the fast pace of this type of natural disaster, a great emphasis was placed on individual initiative and problem-solving. Fortunately, Caltrans has already been in the freeway building business for a half-century. In the office, we already had as-built plans, aerial photographs, survey data and engineers familiar with the structures. All that remained was to rebuild what was there, which also meant no cumbersome environmental review process was necessary. Engineers and traffic managers designed temporary traffic detours at the same time permanent bridge designs were being done. Within the design branches, certain staff was assigned to task forces to work on particular projects with the goal of getting the plans, specifications and estimates done as quickly as possible. To create emergency detours, a senior design engineer familiar with the area was teamed with a traffic engineer and asked to come up with the safest and most efficient routes around damaged structures. Using the as-built plans, often the designs were done by hand. The designer was then dispatched to the field to work with Maintenance Branch employees to implement the detour.
Management Structure
The existing hierarchy for decision-making was used, with the additional overlay of a quake recovery task force led by Business, Transportation and Housing Agency Secretary Dean Dunphy. The task force's main objective was to make sure all agencies were coordinating their efforts, and to remove any roadblocks to rapid rebuilding. After a few weeks, the task force realized that the recovery was on track and met only on an as-needed basis.
Beyond the task force, District 7 was pretty much in charge of quake recovery. The district director held daily meetings with his division chiefs, who then in turn often met with their branch chiefs to pass on instructions. After about two weeks, Division Chief Jack Hallin, who had just finished overseeing the $2.2 billion completion of the Century Freeway, was made project manager of the quake recovery. Problems were sent up the ladder and quickly resolved by the project manager or, if necessary, the task force, which was represented by all the major agencies involved in the recovery effort.
Even when the normal chain of command was disrupted, work progressed rapidly. The regional director for traffic operations, Chuck O'Con-nell, lived near the quake's epicenter and his home sustained severe damage. He was unable to report to work for a week. The office chief for Traffic Systems, likewise, was on a European vacation, and the office chief for Traffic Investigations was also out of town. The monumental task of managing virtually the entire earthquake from a traffic management point of view was left to Raja Mitwasi, the energetic branch chief of the District 7 High Occupancy Vehicle Lane Task Force. He performed admirably under extraordinary circumstances.
The 118 Freeway rebuilding nears completion.
To augment our own personnel, District 7 drew upon maintenance, engineering and administrative personnel from other neighboring districts as well as from the Caltrans headquarters in Sacramento. Mitwasi usually fielded the offers of help from other districts, and put them in touch with the branch chief of that functional area to make sure the additional people were needed and could be utilized properly.
From the outset, everyone at Cal-trans was prioritizing. Earthquake recovery was given top priority over everything else. Within the earthquake recovery, structures engineers were making decisions on which bridges were damaged and which were not, which could support traffic and which should be closed. Traffic was deciding which detours should be opened first, and engineers were deciding which bid packages to prepare first.
LESSONS LEARNED
The quake recovery effort was not without its problems, and communication topped the list. The advent of beepers and, more importantly, cellular phones was critical for the District Office to get in touch with field personnel. Caltrans quickly discovered that it didn't have enough phones to go around. Fortunately, a local cellular telephone company loaned field personnel phones during the crisis.
Another bottleneck developed over bridge inspections. In the event of a disaster, there are simply not enough structural engineers available to do immediate inspections of the thousands of bridges in the highway system. The aftershocks also complicated inspection efforts, forcing engineers to visit bridges more than once. Eventually, the quake zone was divided into subregions, and teams of engineers were sent to inspect bridges, soundwalls and other structures within the given subregions. The information was then compiled into a quake damage database, which included a description of the damage and cost estimate to repair.
Simple logistical matters also became irritants during the quake recovery. Our Traffic Management Center soon found out that they did not have adequate maps to work out the detours, and the list of home numbers for senior traffic engineers was outdated, leading to delays in contacting key people immediately after the quake, which struck on the Martin Luther King Jr. holiday.
The Northridge earthquake wasn't the end of the world, or even the end of Los Angele. But it did lay to rest the lingering doubts about the resiliency of LA. and its ability to rally behind a common cause. At least until the next
Interestingly, one recurrent problem never manifested itself during the quake recovery: inter-agency rivalry. All agencies involved in the effort, including the California Highway Patrol, the City and County of Los Angeles, the Metropolitan Transportation Authority, and the City of Santa Clarita, all cooperated fully.
PREVENTING FUTURE DAMAGE
The Northridge earthquake presented far more than a challenge to find ways around quake damage, and to see how quickly freeways could be rebuilt. It also placed renewed scrutiny on our ambitious Seismic Retrofit program that aims to strengthen hundreds of older freeway bridges to help them withstand the most powerful earthquakes. The Santa Monica Freeway was among the bridges identified for seismic retrofitting, and construction was scheduled to begin within a month of the Northridge earthquake. All 122 of the bridges that had been retrofitted in that way were not damaged in the Northridge earthquake, which is a reallife testament to the value and integrity of those new designs. Everything Cal-trans learned in the area of earthquake safety is going into these designs.
Currently the Seismic Retrofit program involves strengthening the columns of existing bridges by encircling certain columns with a steel casing or, in a few cases, an advanced woven fiber casing. In addition to the column casing, some of the bridge footings are made bigger and given additional support by placing additional pilings in the ground or by using steel tie-down rods to better anchor the footings to the ground. In a few cases bridge abutments are made larger and the past restrainer units are made stronger as encasing the columns make them stiffer and can change the way forces are transmitted within the bridge.
Originally Caltrans had planned to retrofit 1,039 bridges with the column casing and footing strategy. After the Northridge quake, Caltrans launched a review of another 1,655 bridges statewide to determine if they needed retrofit work. In addition, Caltrans went back and reviewed another 700 bridges statewide that had been determined not to need any retrofit work as a check on the process and to make sure no possible bridges that could need retrofit had been overlooked.
As it stands now, there will be 2,403 bridges retrofitted statewide in Phase One and Phase Two of the retrofitting program, out of 12,000 state-owned bridges. The goal for the entire seismic safety program is to have it completed by 1997. In District 7, Los Angeles and Ventura counties, there are a total of 701 bridges to be retrofitted out of a total of 2,566 bridges in the district.
PULLING TOGETHER
In the first hours and days after the Northridge earthquake, things looked pretty grim for Los Angeles. In the past two years we've endured a riot, raging wildfires, and drought punctuated by an occasional flood. Now there's talk that killer bees are on the way. And then the earthquake. Some doom-say-ers predicted that it could be years before the freeways were restored. But, as it always does, L.A. pulled together to respond to the earthquake crisis. As it stands now, earthquake repair of the major freeways will be done by December—in less than a year—and our Seismic Retrofit program is well on its way to fortifying hundreds of other bridges in L.A. to help them withstand another great quake.
Indeed, the Northridge earthquake wasn't the end of the world, or even the end of Los Angeles. But it did lay to rest the lingering doubts about the resiliency of L.A. and its ability to rally behind a common cause. At least until the next earthquake. ❑
Jerry B. Baxter, a 34-year Caltrans veteran, held virtually every position in District 7's organizational ladder before being named director in 1987. He has an A.A. from Hannibal La Grange College, a B.S.C.E from the University of Southern California, and has participated in postgraduate progams.
He is involved with the Executive Committee of the American Public Works Association; Administrative Committee of the International Bridge, Tunnel and Turnpike Association; and the Policy Committee of I.V.H.S. (Intelligent Vehicle/Highway System) America.
Mr. Baxter is a native of Hannibal, Missouri. He and his wife, Connie, have two married daughters and a son. His hobbies include fishing and hunting.
