Estimation of Fatigue Life of Long-Span Bridge by Considering Vehicle-Bridge Coupled Vibration
To estimate the fatigue life of long-span steel bridge more accurately, this paper proposes a method for estimating the fatigue life of long-span bridges by considering vehicle-bridge coupled vibration. Firstly, the universal equation of vehicle-bridge vibration is derived based on triaxial standard multi-scale model of fatigue vehicle and bridge, and relevant program for vehicle-bridge coupled vibration is programmed. Secondly, a method for estimating the fatigue life of long-span steel bridge is proposed based on fracture mechanics theories, and the analysis process is expounded in details. Finally, the method for estimating fatigue life proposed in this paper is verified by taking a double pylon cable- stayed bridge with orthotropic steel bridge deck slab as an example.
Spectra of Road Surface Roughness on Bridges
The power spectral density (PSD) of road surface roughness on highway bridges is presented. Eighty-four lines of 56 bridges were measured and the road surface roughness was measured by surveyor's level. The PSD is assumed by a stationary normal probability process with a zero mean value, and is calculated by a maximum entropy method (MEM) to a measured value of road surface roughness. Numerical examples are presented to obtain the information of road surface roughness on bridges in spectral characteristics, and to give the appropriate PSD using the dynamic response analysis of bridges under moving vehicles.
Impact of cancer-related fatigue on the lives of patients: new findings from the Fatigue Coalition.
PURPOSE
This survey was designed to confirm the prevalence and duration of fatigue in the cancer population and to assess its physical, mental, social, and economic impacts on the lives of patients and caregivers. Patients and Methods. A 25-minute telephone interview was completed with 379 cancer patients having a prior history of chemotherapy. Patients were recruited from a sample of 6, 125 households in the United States identified as having a member with cancer. The median patient age was 62 years, and 79% of respondents were women. Patients reporting fatigue at least a few times a month were asked a series of questions to better describe their fatigue and its impact on quality of life.


RESULTS
Seventy-six percent of patients experienced fatigue at least a few days each month during their most recent chemotherapy; 30% experienced fatigue on a daily basis. Ninety-one percent of those who experienced fatigue reported that it prevented a "normal" life, and 88% indicated that fatigue caused an alteration in their daily routine. Fatigue made it more difficult to participate in social activities and perform typical cognitive tasks. Of the 177 patients who were employed, 75% changed their employment status as a result of fatigue. Furthermore, 65% of patients indicated that their fatigue resulted in their caregivers taking at least one day (mean, 4.5 days) off work in a typical month. Physicians were the health care professionals most commonly consulted (79%) to discuss fatigue. Bed rest/ relaxation was the most common treatment recommendation (37%); 40% of patients were not offered any recommendations.


CONCLUSIONS
Cancer-related fatigue is common among cancer patients who have received chemotherapy and results in substantial adverse physical, psychosocial, and economic consequences for both patients and caregivers. Given the impact of fatigue, treatment options should be routinely considered in the care of patients with cancer.