Journal of Performance of Constructed Facilities

In this study the seismic performance of flat plate system structures designed without considering seismic load was investigated. Both the capacity spectrum method provided in ATC-40 in 1996 and nonlinear dynamic analyses were carried out to obtain maximum interstory drifts for earthquake loads. Also, a seismic performance evaluation procedure presented in FEMA-355F in 2000 was applied to evaluate the seismic safety of the model structures. The analysis results showed that the maximum interstory drifts of the nonseismic designed flat-plate structures computed by the capacity spectrum method and the nonlinear dynamic analysis were smaller than the limit state for the collapse prevention performance level. However, the results of the FEMA procedure showed that the model structures did not have enough strength to ensure seismic safety.

The results of a multifaceted investigation into large-amplitude vibrations of bridge stay cables are presented. The vibration of the stay cables occurred under light rain and wind conditions, and resulted in low-frequency, large-amplitude oscillations having recorded displacements of over $24\mathrm{in.}$ $\left(0.6\mathrm{m}\right)$ . Due to concerns about the implications of the vibrations on the integrity and durability of the stay cables and observed damage to stay-cable anchorage components, an investigation and repair program was developed. The final repair program arose from an investigation that combined the talents of practicing engineers, the Texas Department of Transportation, and representatives from four universities. Ultimately, a combination of supplemental hydraulic dampers and cable restrainers were used to mitigate the vibrations. This paper describes the results of the investigation and presents the practice-based methodology used to develop the implemented repair program.

Two highway bridge approaches, about 10 and $12\mathrm{m}$ in height, near Kolkata (Calcutta), India constructed with mechanically stabilized earth (MSE) failed recently. These structures were founded on sensitive, soft and compressible, fine-grained soils of the intertidal flats and backswamps of the Ganges delta. One of these MSE walls, which failed in the final stages of its construction, was constructed after foundation soils were strengthened with prefabricated vertical drain installation and preloading. The second MSE wall that failed within a month of its opening for traffic was constructed on unimproved ground. Fortunately, immediate collateral damage from these incidents was small. Using pre and postconsolidation shear strengths the MSE walls were redesigned. Reconstruction involved prefabricated vertical drain installation at the second site and construction of stabilizing berms at both locations. The facilities are now operational and appear to be performing satisfactorily. Details of the failures, postfailure investigations, and monitoring, redesign, and reconstruction are presented in this paper.

Sand compaction piling is one of the commonly used countermeasures for earthquake liquefaction hazard of river dikes. This paper presents a case study of the performance of an instrumented dike in northeast Japan that was improved by sand compaction piles and subjected to the 2003 Northern Miyagi Earthquake, with the aim to better understand the effectiveness of this ground improvement method. Simulation has been carried out by means of a fully coupled numerical procedure which employs a sophisticated cyclic elastoplastic constitutive model and the updated Lagrangian algorithm. Comparisons between the field measurements and the computed responses, including the time histories of accelerations and pore-water pressures at different locations, show reasonably good agreement. Numerical simulation has also been made of the same dike but without ground improvement to identify the effects of sand compaction piles in altering the performance of the dike. The study demonstrates that the comprehensive numerical procedure is a promising tool for development of seismic performance-based design of earth structures.

Between 2001 and 2002, a $6.4\text{-}\mathrm{m}$ $\left(21.0\text{-}\mathrm{ft}\right)$ diameter corrugated steel pipe culvert was erected and buried under a $22.9\text{-}\mathrm{m}$ $\left(75.0\text{-}\mathrm{ft}\right)$ highway embankment fill in Meigs County, Ohio. This steel pipe culvert was the first of its kind to be constructed in the southeastern region of Ohio. The culvert structure was selected by the Ohio Department of Transportation over an alternative of a 5 million conventional bridge structure, because it would cost about $3.4 million less. The field performance of the culvert was monitored by measuring the pressure distribution around the pipe, as well as the deflections of the pipe culvert during and after construction. The culvert study also included comparing measured field performance with numerical predictions given by the finite-element computer program CANDE-89. CANDE-89 with the slotted joint option had a limited ability to simulate the actual field behavior of the large-diameter multiplate culvert structure, especially in the earlier stages of construction.

As agencies continue looking for cost-effective methods to rehabilitate deteriorated jointed concrete pavement (JCP), rubblization using a resonant breaker has been experimented by the Shanghai Municipal Roadway Authority (SMRA). It was demonstrated that rubblization using a resonant breaker offers a viable option for the SMRA because the rubblized pavement sections have been performing very well with no visible distress. Based on field observation for a typical hot mix asphalt concrete (HMAC) overlay on a nonrubblized JCP, it was found the treatment normally would have reflective cracking for the same overlay thickness in the first three years. Besides the cost advantage over the reconstruction, a resonant breaker also had yielded the minimum disturbance during the rubblization. It was observed that it was very effective to use water during compaction on a rubblized JCP surface to improve compaction efficiency and to control dust. Furthermore, there is no need to apply a prime coat before the HMAC overlay, as there was no detrimental effect that could be identified. The average rubblized JCP moduli were found to be $\mathrm{1,323}\text{to}\mathrm{1,375}\mathrm{MPa}$ , which are within the range reported in the literature. It was believed that there were high possibilities to increase rubblized JCP moduli without sacrificing the performance by increasing the particle size, because a reduction of $200\mathrm{mm}$ of HMAC was observed when rubblized JCP increased from $345\text{to}\mathrm{3,445}\mathrm{MPa}$ at a subgrade modulus of $138\mathrm{MPa}$ and traffic of 30 million ESAL. However, further research is needed to optimize the rubblized JCP moduli in an attempt to reduce overlay thickness without creating reflective cracking.

In the past few years, a number of full-depth or perpetual pavements have been designed and constructed in the State of Texas. A study was conducted to examine the quality of the compaction of the thick asphalt layers within these pavements using advanced forensic tools such as X-ray computed tomography (X-ray CT) and ground penetrating radar (GPR). The GPR is a nondestructive tool for evaluating the uniformity of density in pavements at highway speed. X-ray CT is a laboratory tool that is used to conduct detailed analysis of air void distribution and uniformity in asphalt pavement cores. This paper presents the results of analyzing one of the perpetual pavements constructed in State Highway 114 (SH-114). In this project, two different structural asphalt pavement sections were placed, one included a $1\mathrm{in.}$ (25.4 mm) stone filled (SF) Superpave mix and the other included a traditional dense graded Type B material. The dense graded Type B material was found to be uniformly compacted. However, major compaction problems were identified with the coarse SF Superpave mix. The poor compaction and associated high percent air vsoids were found to permit moisture infiltration, which could potentially lead to rapid pavement deterioration. The analysis showed very good agreement between the GPR and X-ray CT results and demonstrated the efficiency of using GPR and X-ray CT in the evaluation of asphalt pavement compaction.