Integrated Design/Construction/Operations Analysis for Fast-Track Urban Freeway Reconstruction

The California Department of Transportation is rehabilitating or reconstructing deteriorated urban freeways using long-life (30+ years) strategies. These pavements were constructed between 1955 and 1970 with design lives of 20 years. This paper summarizes preconstruction analysis of the fast-track pavement reconstruction on Interstate-15 (I-15) at Devore which used two one-roadbed continuous (about 210 h) closures with round-the-clock (24/7) operations. The integrated analysis concluded that the one-roadbed continuous closures are the most economical scenario when compared to traditional nighttime or weekend closures from the perspective of schedule, delay, and costs. The preconstruction was validated with as-built construction and traffic performances monitored during construction. The construction management plan—including contingency, incentives, and critical path method schedule—was developed utilizing the Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) computer model. The results of this planning study are useful for transportation agencies in developing highway rehabilitation strategies that balance the maximization of construction productivity with a minimization of traffic delay.     

Productivity Aspects of Urban Freeway Rehabilitation with Accelerated Construction

Over the last 5?years the California Department of Transportation (Caltrans) has completed three experimental long-life urban freeway rehabilitation projects by utilizing a fast-track (accelerated) construction approach of around-the-clock operations under extended closure. This paper presents the fast-track rehabilitation approaches and the as-built production rates of major rehabilitation operations monitored at the three experimental projects. The monitoring results show that the contractor’s production rates varied considerably depending upon the construction logistics, material delivery and hauling methods, lane-closure tactics, and/or pavement designs being implemented. A higher production rate and a noticeable “learning-curve effect” were observed when full-width rehabilitation was compared with partial-width rehabilitation, when continuous lane reconstruction was compared with random slab replacements, and when full roadbed closures were compared with partial lane closures. Findings in this study suggest that Caltrans should evaluate project-specific conditions and constraints, which might restrict use of a preferred rehabilitation scheme, by taking production rate variances into account when establishing schedule baselines of construction staging plans and incentive/disincentive contracts for urban freeway rehabilitation projects.     

Computer Simulation Model: Construction Analysis for Pavement Rehabilitation Strategies

Most state highways in the United States were built during the 1960s and 1970s with an infrastructure investment of more than $1 trillion. They now exceed their 20?year design lives and are seriously deteriorated. The consequences are high maintenance and road user costs because of degraded road surfaces and construction work zone delays. Efficient planning of highway rehabilitation closures is critical. This paper presents a simulation model, Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS), which estimates the maximum amount of highway rehabilitation/reconstruction during various closure timeframes. The model balances project constraints such as scheduling interfaces, pavement materials and design, contractor logistics and resources, and traffic operations. It has been successfully used on several urban freeway rehabilitation projects with high traffic volume, including projects on I-10 and I-710. The CA4PRS helps agencies and contractors plan highway rehabilitation strategies by taking into account long-life pavement performance, construction productivity, traffic delay, and total cost.     

Developing a Traffic Closure Integrated Linear Schedule for Highway Rehabilitation Projects

In recent years, the state departments of transportation have implemented a number of highway rehabilitation projects across the country. These projects differ fundamentally from new highway projects in that they require an uninterrupted flow of traffic throughout both the duration and geometric length of the project. Synchronization of traffic closure with the construction activities is crucial in such projects to avoid the traffic conflicts and prevent idle time for equipment and labor. Although most highway rehabilitation projects involve predominantly linear activities, the techniques of linear scheduling are not readily applicable to highway rehabilitation projects due to the conflict between the workzone and traffic flow. This paper documents the development of a traffic closure integrated linear schedule (TCILS) that addresses both traffic closure and work progress issues. The TCILS generates a single schedule for both the construction activities and the associated traffic closures. Visual and graphical features are also applied in the system, which makes it particularly applicable for highway rehabilitation projects. An actual concrete pavement rehabilitation project using the TCILS is presented as a sample of application. The findings from the sample project, although they are limited, show that the TCILS can be applied to an actual project. With recommended future development, the system is believed to be beneficial for both construction practitioners and academics.     

Weekend Closure for Construction of Asphalt Overlay on Urban Highway

Construction of asphalt overlays for urban highways is generally restricted to off-peak hours, often exclusively nighttime hours, and to partial closures to minimize public inconvenience. Such constraints are thought to adversely affect production and quality. In August 1997, the Washington State Department of Transportation implemented a pilot project to evaluate the option of a full weekend closure—closure of all lanes in a single direction throughout designated weekend hours—as an alternative to nighttime closures. Two concerns were consistent construction quality between nighttime and daytime paving and general comparison of the full weekend closure with other closure strategies. Surface smoothness (rideability) and in-place density were compared between nighttime and daytime mainline paving for this project, and gradation and asphalt cement content variabilities were compared with published average values. Production rates were compared to those from a comparably sized nighttime project. The investigation revealed that consistent quality, exceeding reported average values, may be achieved. High paving production rates resulted from close proximity of the hot mix plant to the work zone.     

Seismic Restrainer Design Methods for Simply Supported Bridges

Existing restrainer design methods recommended by the American Association of State Highway and Transportation Officials (AASHTO) and the California Department of Transportation (Caltrans) to prevent unseating in simply supported bridges subjected to strong earthquakes were evaluated. Three new methods with different levels of complexity were developed: W∕2, modified Caltrans, and the equivalent linear static design for restrainers. The adequacy of different design methods was assessed using a nonlinear response history analysis computer program. Effects of different earthquakes, substructure stiffness, bearing strength, seat width, and skew angle were studied. It was found that in bridges with reinforced concrete pier caps the inherently wide supports help prevent unseating, and simple methods such the AASHTO and W∕2 method are satisfactory. In bridges with steel pier caps that provide narrow bearings the modified Caltrans method is recommended. The relatively involved equivalent linear static design for restrainers method is a more rational design procedure and leads to considerably fewer restrainers than others.     

Use of the Long-Term Pavement Performance Database in the Pavement Engineering Curriculum

In this paper the writers demonstrate the inclusion of the Long-Term Pavement Performance (LTPP-DATAPAVE 3.0) data within the pavement engineering curriculum at Michigan State University (MSU). The paper presents two examples, one from an undergraduate course on pavement rehabilitation and one from a graduate course on pavement analysis and design. These examples illustrate the use of LTPP data in computing responses, predicting traffic, developing rehabilitation strategies, and predicting performance of both rigid and flexible pavements.     

Forensic Investigation of Ultrathin Whitetopping Pavements in Florida

Developed in the early 1990s, ultrathin whitetopping (UTW) is a relatively new technique for asphalt pavement rehabilitation. To evaluate the applicability of UTW pavement in Florida, in 1997, the Florida Department of Transportation (FDOT) constructed an experimental UTW pavement in a weigh station along I-10, located in north Florida. The performance of these test sections, however, was less than ideal, with the observation of some early cracking on the concrete surface, which developed into severe cracking with time. Therefore, a forensic investigation was conducted to determine the causes of the problems in these UTW sections, so that lessons could be learned from this experimental project, the use of UTW under Florida’s conditions could be adequately assessed, and UTW technology could be properly applied in the future. The scope of work consisted of field evaluation, laboratory testing, and pavement design evaluation. Field evaluation included a pavement condition survey, pavement temperature measurement, nondestructive load testing using a falling weight deflectometer, and slab thickness determination. Laboratory tests were performed to determine concrete and asphalt material properties. Other design and traffic data were also acquired from FDOT. Data collected from the field evaluation and laboratory testing were used in conjunction with a mechanistic UTW pavement design/evaluation procedure to determine the possible causes for premature failure. From this comprehensive evaluation, the primary cause for the failure was found to be inadequate UTW pavement design. The inadequacy of the combination of thickness and slab dimensions contributed to the early cracking of the UTW pavement.     

Successful Application of CLSM on a Weak Pavement Base/Subgrade for Heavy Truck Traffic

Lack of proper pavement base and subgrade compaction leads to premature failures that account for millions of dollars in damages. Controlled low-strength material (CLSM) concrete was introduced in this study as pavement base material near a manhole where proper compaction is unachievable. Rut-resistant stone matrix asphalt was placed on top of the CLSM as a wearing surface layer. Dynamic cone penetrometer (DCP) testing was used to monitor CLSM construction. One day after placing, the CLSM gained sufficient strength to support construction traffic. Further, DCP results indicated that the CLSM possessed uniform characteristics of concrete that could improve the load-bearing capacity and serviceability of the pavement near the manhole. After 18 months of heavy truck traffic, maximum rutting was 5?mm, well below the failure criteria of 12.5?mm. Based on cost and performance, CLSM concrete has the potential to improve problematic areas in pavement.     

CONLIGHT: Lighting Design Model for Nighttime Highway Construction

The utilization of nighttime work in highway construction and rehabilitation projects has been increasing in recent years throughout the United States. In this type of projects, construction planners are required to develop and submit a lighting plan that provides: (1) adequate illuminance levels for all planned nighttime construction tasks; (2) reasonable uniformity of light distribution in the work area, and (3) acceptable glare levels to both road users and construction workers. In order to support construction planners in this vital and challenging task, this paper presents a lighting design model, named CONLIGHT, which is capable of considering the specific requirements of nighttime highway construction operations. The model is developed to enable construction planners to evaluate the performance of various lighting plans and select a practical design that complies with all lighting requirements for the nighttime work being planned. An application example is analyzed to illustrate the use of the model and demonstrate its accuracy and capabilities in generating practical lighting plans for nighttime construction and rehabilitation projects.     

State-of-Practice Technologies on Accelerated Urban Highway Rehabilitation: I-15 California Experience

This case study paper presents an innovative fast-track approach applied to a heavily trafficked urban freeway reconstruction project in Southern California. Badly deteriorated truck lanes in both directions along a 4.5-km stretch of I-15 were rebuilt from the gravel base up. The operations, estimated to take 10?months using traditional nighttime closures, were completed in two 9-day continuous closures with round-the-clock (about 210?h for each direction) operations. This “Rapid Rehab” project adopted state-of-practice technologies to accelerate construction, mitigate traffic disruptions, and propagate project information. As a result, traffic demand through the construction work zone was reduced by 20% and the maximum peak-hour delay was reduced by 50%. The estimated benefits of accelerated reconstruction on this project included a 28% reduction in agency cost and 29% time value savings to road users, compared to the traditional approach of using repeated nighttime closures. Web surveys showed dramatic changes in public perception of the Rapid Rehab approach from initial reluctance and objection to positive support.     

Bidirectional Pseudodynamic Tests of Bridge Piers Designed to Different Standards

Circular reinforced concrete highway bridge piers, designed in accordance with the requirements of the California Department of Transportation (Caltrans) in the U.S., New Zealand, and Japanese specifications, are experimentally investigated to assess their seismic performance. Pseudodynamic test procedures are developed to perform experiments on 30% scaled models of the three prototype bridge piers. Each specimen is subjected to a sequence of three different earthquake ground motions scaled appropriately to represent: (1) the design basis earthquake (DBE) with a 90% nonexceedance probability; (2) the maximum considered earthquake (MCE) with a 50% nonexceedance probability; and (3) the MCE with a 90% nonexceedance probability. Damage states after the earthquakes are assessed and mapped for seismic risk assessment. The damage outcomes and the corresponding seismic risks validate the objectives of the performance-based design codes of the three countries. The results show that when bridge piers are designed to the specifications of each of the three countries, satisfactory performance with only slight to moderate damage can be expected for DBE. For the MCE, severe damage without collapse is likely for the Caltrans and Japanese piers. However, the NZ pier may not be able to survive MCE motions with sufficient reliability to ensure the preservation of life-safety.     

南海大道东滨路以南段路面病害分析及改造

针对深圳市南海大道沥青混凝土路面出现的各种早期破坏的主要原因进行归类分析,从设计、施工、管理方面初步探讨应对措施和改进办法,以达到提高路面建设投资效能的目的。     

Probabilistic Approaches for Pavement Fatigue Cracking Prediction based on Cumulative Damage Using Miner’s Law

In mechanistic-empirical (M-E) pavement design, pavement damage is modeled as a random variable with a pre-specified distribution (normal or lognormal). The extent of fatigue cracking in terms of percentage cracking is computed as the probability of cumulative damage exceeding unity. This paper provides a methodological framework for characterizing damage distribution under mixed traffic loading (multiple strain levels) with an improved forecast of traffic spectrum based on renewal theory. Using the linear Miner’s law for damage accumulation, analytical representation of damage distribution is obtainable owing to the proportional relationship between maximum tensile strain of pavement and traffic load under linear elasticity condition. Numerical computation shows that percent of cracking from derived damage distribution is greater than that from hypothetical normal or lognormal distributions traditionally used in the M-E pavement design. The method developed here and the derived model can be used in pavement design and pavement management systems.     

Impact of Annual Average Daily Traffic on Highway Runoff Pollutant Concentrations

The objective of this study was to evaluate correlations between annual average daily traffic (AADT) and storm water runoff pollutant concentrations generated from California Department of Transportation (Caltrans) highway sites. Analyses of data collected from the Caltrans four-year (1997–2001) highway runoff characterization program revealed that, in general, pollutant concentrations from urban highways were higher than those found from nonurban highways. For a limited number of pollutants, however, the concentrations from nonurban highways were found to be higher than the concentrations from urban highways. No direct linear correlation was found between highway runoff pollutant event mean concentrations and AADT. However, through multiple regression analyses, it was shown that AADT has an influence on most highway runoff constituent concentrations, in conjunction with factors associated with watershed characteristics and pollutant build-up and wash off. The other noticeable factors shown to influence the accumulation of pollutants on highways were antecedent dry period, drainage area, maximum rain intensity, and land use.     

Effectiveness of Speed Control Measures on Nighttime Construction and Maintenance Projects

Nighttime work-zone safety has become a concern among state transportation agencies due to an increasing number of work-zone fatalities and the high percentage of roadwork performed at night. Speed control has been determined by numerous researchers to be one of the best ways to improve safety on nighttime work zones. This paper presents an empirical analysis of speed-control strategies for nighttime interstate construction and maintenance projects in Indiana. The analysis considers the effect of various speed-control measures on the mean speed and the standard deviation of speed through nighttime work zones. Using a seemingly unrelated regression modeling approach, the present analysis revealed that the presence of police enforcement, a high percentage of semitrucks in the traffic stream, and a high traffic flow significantly reduced mean work-zone speeds. Factors found to significantly increase mean work-zone speeds included an increase in the number of open lanes, an original speed limit of the road section greater than 100 km/h (62 mi/h) an increase in the distance between the work-zone speed-limit signs and the first cone/barrel in the construction zone taper, and the progression of time through the night. The standard deviation of vehicle speeds was found to be significantly lower before midnight and as the number of vehicles queued increased. It was found to be significantly higher with an increase in the number of open lanes through the work zone, an increase in the number of worksite speed-limit signs, a high percentage of personal vehicles in the traffic, and an increase in total traffic flow. The results from this research demonstrate a useful analysis methodology (seemingly unrelated regression estimation) and provide some empirical results that can provide guidance for transportation agencies and contractors to improve speed-control strategies in nighttime work zones.     

Detailed Forensic Investigation and Rehabilitation Recommendation on Interstate Highway-30

The main objective of this study is to identify the cause of the punchouts observed on Interstate Highway 30 (IH-30), and to identify possible rehabilitation alternatives. Several nondestructive tests, as well as coring and trenching, were conducted in both distressed and nondistressed areas. Middepth horizontal cracks were found during routine repair and by the trenching performed in this study. It is believed that due to temperature variation at an early stage, horizontal cracks developed at the middepth interface between the steel and concrete. The truck traffic caused the horizontal cracks to deteriorate further. Repetitive truck traffic and thermal loading forced the concrete to crack vertically from the middepth where there were horizontal cracks. The closely spaced transverse and longitudinal cracks, along with the delamination, caused punchouts. Although the problem is not imminent, an immediate seal plus a 75 mm heavy-duty stone matrix asphalt (SMA) overlay will probably provide the most cost-effective remedy for this section of IH-30. Existing distressed areas should be repaired before the rehabilitation. To slow the deterioration, the district should use a latex modified chip seal or asphalt rubber seal (AC15-5TR) followed by a 75 mm heavy duty SMA. This is to provide bonding between the concrete and SMA overlay. If the district chooses to do nothing at this time, it will become costly in 2–3 years if current environmental and traffic conditions hold. The cost to repair a severely deteriorated continuously reinforced concrete pavement (CRCP) would be several times more than the 75 mm heavy duty SMA overlay.     

窨井周边沥青混凝土路面病害分析与整治

分析了城市道路中窨井周围沥青混凝土路面产生凹陷、麻面、开裂、脱落、龟裂等病害的原因，并结合自己的工作实际从施工队伍的管理，窨井的砌筑，路面的施工等三个方面阐述了消除上述病害的整治措施。     

Factors Affecting Initial Roughness of Concrete Pavement

Past studies have shown that initial pavement roughness greatly affects future pavement roughness and roughness progression rate. Initial pavement roughness is also an important input to the roughness prediction model in mechanistic-empirical design guide. This study analyzed the design and construction factors affecting initial pavement roughness. Initial international roughness index of 90 concrete pavements constructed in Wisconsin from 2000 to 2004 were analyzed using multiple regression method. The factors considered in this study included concrete pavement slab thickness, project location, dowel bar placement, joint spacing, base type, and pavement length. The factors affecting initial pavement roughness were identified.