DEEP EXCAVATION TECHNIQUES FOR SHELTERS IN URBAN AREAS. PRELIMINARY PLANNING AND COST DATA

1963 ◽  
Author(s):  
DE LEUW CATHER AND CO CHICAGO IL
Author(s):  
Christopher R. Cherry ◽  
Eric Tang ◽  
Elizabeth Deakin ◽  
Alexander Skabardonis

In many urban areas, high-occupancy vehicle (HOV) lanes have been provided to permit carpools and express buses to bypass congestion and offer a significant travel time advantage to commuters willing to share a ride or take transit. In many locations, however, HOV lanes are incomplete because of difficulties in securing right-of-way or funding. In other locations, because existing HOV lanes are underutilized, express buses are undersubscribed, or both, questions about their value arise. In this research it is shown how a PARAMICS microscopic traffic simulation model can be used to analyze proposed HOV lanes and their effects on express bus operation along an urban freeway corridor. A PARAMICS application is developed for Interstate 580 in the San Francisco Bay Area and used to test alternative ways of providing HOV lanes. The performance of the corridor is evaluated under plausible scenarios of traffic growth. Traffic simulation models are usually used for detailed operations management. The case study shows that traffic simulation can be an effective preliminary planning and scenario testing tool for evaluating the likely performance of an infrastructure or operations improvement on express bus service.


2018 ◽  
Vol 146 ◽  
pp. 02012 ◽  
Author(s):  
Jarosław Rybak ◽  
Alexander Ivannikov ◽  
Elena Kulikova ◽  
Tomasz Żyrek

Deep excavation and tunnelling works in city centres always bring some risks to surrounding structures, especially in the case of old town centres, where the technical condition and structural stiffness of historical buildings is rather doubtful. When the new desired excavation depth goes deeper than the foundation of the surrounding buildings or when tunnelling works are conducted directly under them, the existing objects are subject to stress, vibrations and displacements imposed at almost every stage of building the new construction. The presented paper outlines, on the basis of the authors’ experience, the typical damages appearing during the supporting wall construction (sheet pile driving, piling and formation of diaphragm walls) and tunnelling works. Other damages appear due to soil mass unloading (caused by excavation stages) and horizontal loading during pre-stressing of struts or ground anchors. The selected case studies of steel sheet pile wall installation is given with regard to typical failures caused by an unplanned excavation and its impact on neighbouring structures.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
X. W. Ye ◽  
L. Ran ◽  
T. H. Yi ◽  
X. B. Dong

In recent years, China has been undergoing a metro railway construction boom in order to alleviate the urban traffic congestion problem resulting from the rapid urbanization and population growth in many metropolises. In the construction of metro systems, deep excavations and continuous dewatering for construction of the metro tunnels and stations remain a challenging and high risk task in densely populated urban areas. Intelligent computational methods and techniques have exhibited the exceptional talent in dealing with the complicated problems inherent in the deep excavation and dewatering practice. In this paper, an intelligent risk assessment system for deep excavation dewatering is developed and has been applied in the project of Hangzhou Metro Line 1 which is the first metro line of the urban rapid rail transit system in Hangzhou, China. The specific characteristics and great challenges in deep excavation dewatering of the metro-tunnel airshaft of Hangzhou Metro Line 1 are addressed. A novel design method based on the coupled three-dimensional flow theory for dewatering of the deep excavation is introduced. The modularly designed system for excavation dewatering risk assessment is described, and the field observations in dewatering risk assessment of the airshaft excavation of Hangzhou Metro Line 1 are also presented.


2021 ◽  
Vol 18 (1) ◽  
pp. 2-14
Author(s):  
Arefeh Arabaninezhad ◽  
Ali Fakher

Deep excavations in urban areas impose deformation to adjacent structures; hence the reliability of deformation analysis for the real deep excavation projects is very important to be assessed. In this study a framework is presented for the use of reliability methods in deformation analysis of deep urban excavations. The suggested framework is applied for 5 real deep excavation projects implemented during last 10 years. All studied cases were recognized as projects of high importance in urban areas, and were monitored during the excavation process. A non-probabilistic reliability analysis procedure, Random set method, in combination with finite element numerical modeling is applied to obtain the probability of unsatisfactory performance for each case. The reliability analysis results are confirmed by field observations and measurements. Typical results for the probability of analytical deformations exceeding the acceptable values along with the site observations and measured displacements for 5 real deep excavation projects show that the reliability analysis could be a beneficial tool for designer. It is concluded that applying the suggested framework in the design stage of deep excavation projects may lead to design more appropriate systems compared to common deterministic design methods.


1996 ◽  
Vol 22 (3) ◽  
pp. 167-174
Author(s):  
J A Cantrill ◽  
B Johannesson ◽  
M Nicholson ◽  
P R Noyce

2001 ◽  
Vol 60 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Holger Schmid

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.


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