CENTRIFUGE MODELING OF LARGE DIAMETER UNDERGROUND PIPES SUBJECTED TO HEAVY TRAFFIC LOADS

impose uncertainties on pipe design. This paper describes the procedure and results of a series of geotechnical centrifuge tests performed on a large 1400 mm-diameter reinforced concrete pipe with a footing subjected to heavy traffic loading. The influence of soil cover depth, as well as the positions and magnitude of traffic loads, on the bending moments of the pipe were investigated. A heavy truck with a maximum load of 850 kN was simulated in the majority of the tests, and a medium truck of 252 kN was also simulated. The centrifuge test results were found to be in reasonable agreement with those from full-scale tests. The pipe would experience the most unfavorable conditions when the heaviest axis of the traffic vehicle was located directly above the pipe crown. A deeper soil cover would lead to higher initial stresses in the pipe, as well as reduced influence of traffic load. However, even for a soil cover depth of 4 m, there is significant bending moment induced by the heavy truck loading, which could not be ignored during the pipeline design. Comparison was made between the centrifuge test results and several widely adopted design methods, and unconservative calculation results were noticed for large diameter rigid pipes lying at a shallow soil cover depth subjected to heavy traffic loading.

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Centrifuge modeling of large-diameter underground pipes subjected to heavy traffic loads

Canadian Geotechnical Journal ◽

10.1139/cgj-2013-0253 ◽

2014 ◽

Vol 51 (4) ◽

pp. 353-368 ◽

Cited By ~ 21

Author(s):

Boris Rakitin ◽

Ming Xu

Keyword(s):

Soil Cover ◽

Heavy Traffic ◽

Large Diameter ◽

Traffic Load ◽

Initial Stresses ◽

Centrifuge Test ◽

Test Results ◽

Traffic Loading ◽

Cover Depth ◽

Traffic Loads

Large-diameter pipes, as well as heavy vehicles, have become increasingly prevalent, which imposes uncertainties on pipe design. This paper describes the procedure and results of a series of geotechnical centrifuge tests performed on a large 1400 mm diameter reinforced concrete pipe subjected to heavy traffic loading up to 850 kN. The influence of soil cover depth, as well as the positions and magnitude of traffic loads, on the bending moments of the pipe were investigated. The centrifuge test results were found to be in reasonable agreement with those from full-scale tests. The pipe would experience the most unfavorable conditions when the heaviest axle of the traffic vehicle was located directly above the pipe crown. A deeper soil cover would lead to higher initial stresses in the pipe, as well as reduced influence of traffic load. However, even for a soil cover depth of 4 m, there is significant bending moment induced by the heavy truck loading, which cannot be ignored during pipeline design. A comparison was made between the centrifuge test results and several widely adopted design methods, and unconservative calculation results were noticed for large-diameter rigid pipes lying at a shallow soil cover depth subjected to heavy traffic loading.

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Effect of variation of the loading direction on the displacement accumulation of large-diameter piles under cyclic lateral loading in sand

Canadian Geotechnical Journal ◽

10.1139/cgj-2013-0438 ◽

2014 ◽

Vol 51 (10) ◽

pp. 1196-1206 ◽

Cited By ~ 27

Author(s):

Christina Rudolph ◽

Britta Bienen ◽

Jürgen Grabe

Keyword(s):

Large Diameter ◽

Offshore Structures ◽

Simple Approach ◽

Lateral Loading ◽

Small Scale ◽

Centrifuge Test ◽

Test Results ◽

Loading Direction ◽

Stress Levels ◽

Transverse Movement

Foundation piles supporting offshore structures experience cyclic lateral loading arising from waves and wind, which are not typically uni-directional over the lifetime of the structure. This paper presents results from centrifuge experiments in sand, representing a large diameter prototype tested at stress levels similar to the field subjected to cyclic lateral loading from varying directions. The results demonstrate increased deformation accumulation due to the changing loading direction, compared to the uni-directional case. Displacement accumulation is not limited to the main loading direction but includes transverse movement as well. Similar trends were observed in small-scale 1g modelling that allowed a larger number of load cycles to be applied. The centrifuge test results provide confidence of the applicability of the findings to the prototype. Current methods that neglect the effect of variation of the loading direction will provide predictions of displacement accumulation of piles that are un-conservative. Therefore, a simple approach is proposed here to estimate the augmentation of displacement accumulation due to variation in loading direction compared to the uni-directional case.

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Numerical study using stiffness parameters on the nonlinear behavior of RCA pavements under heavy traffic loads

Transportation Geotechnics ◽

10.1016/j.trgeo.2021.100582 ◽

2021 ◽

pp. 100582

Author(s):

Merve Akbas ◽

Bilal Özaslan ◽

Hadi Khanbabazadeh ◽

Recep İyisan

Keyword(s):

Numerical Study ◽

Heavy Traffic ◽

Nonlinear Behavior ◽

Traffic Loads

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Evaluation of Fatigue Properties for Ultraviolet Radiation Aged Bitumen and Mixture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.181 ◽

2011 ◽

Vol 217-218 ◽

pp. 181-186

Author(s):

Shao Peng Wu ◽

Jun Han ◽

Xing Liu

Keyword(s):

Ultraviolet Radiation ◽

Heavy Traffic ◽

Testing Machine ◽

Road Construction ◽

Fatigue Properties ◽

Repeated Loading ◽

Uv Aging ◽

Traffic Loads ◽

Universal Testing ◽

Layered Clay

Bitumen is widely used in road construction. Due to heavy traffic loads and environmental factors, bitumen properties will change during service life. Bitumen will age due to diffusion of oxygen and UV radiation. Repeated loading will result in decreasing strength because of fatigue. In this paper, one layer clay powder was used to modify base bitumen with different mass contents. Then the influences of ultraviolet radiation (UV) aging on the dynamic fatigue properties of the layered clay powder were evaluated by Dynamic Shear Rheomoter (DSR) and Universal Testing Machine (UTM). The ageing evaluation shows that the ageing resistance of bitumen is improved and this improvement is more notable in bitumen fatigue than mixture.

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Efficient Intrusion Detection for High-Speed Networks

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.263-266.2915 ◽

2012 ◽

Vol 263-266 ◽

pp. 2915-2919

Author(s):

Gao Long Ma ◽

Wen Tang

Keyword(s):

Intrusion Detection ◽

Error Detection ◽

Intrusion Detection System ◽

High Speed ◽

Detection System ◽

Heavy Traffic ◽

High Speed Networks ◽

Network Intrusion ◽

Traffic Loads ◽

Rule Sets

With the great increasing of high-speed networks,the traditional network intrusion detection system(NIDS) has a serious problem with handling heavy traffic loads in real-time ,which may result in packets loss and error detection . In this paper we will introduce the efficient load balancing scheme into NIDS and improve rule sets of the detection engine so as to make NIDS more suitable to high-speed networks environment.

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HEAVY TRAFFIC APPROXIMATIONS FOR A SYSTEM OF INFINITE SERVERS WITH LOAD BALANCING

Probability in the Engineering and Informational Sciences ◽

10.1017/s0269964899133011 ◽

1999 ◽

Vol 13 (3) ◽

pp. 251-273 ◽

Cited By ~ 10

Author(s):

Philip J. Fleming ◽

Burton Simon

Keyword(s):

State Space ◽

Heavy Traffic ◽

Joint Probability ◽

Mass Function ◽

Accurate Estimate ◽

The State ◽

Probability Mass Function ◽

Traffic Loads ◽

Wide Range ◽

Heavy Traffic Approximations

We consider an exponential queueing system with multiple stations, each of which has an infinite number of servers and a dedicated arrival stream of jobs. In addition, there is an arrival stream of jobs that choose a station based on the state of the system. In this paper we describe two heavy traffic approximations for the stationary joint probability mass function of the number of busy servers at each station. One of the approximations involves state-space collapse and is accurate for large traffic loads. The state-space in the second approximation does not collapse. It provides an accurate estimate of the stationary behavior of the system over a wide range of traffic loads.

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BAHAN TAMBAH SERAT ECENG GONDOK PADA LASTON TIPE XI TERHADAP INDEKS MARSHALL TEST MENGGUNAKAN KERIKIL MANTUP

UKaRsT ◽

10.30737/ukarst.v2i2.269 ◽

2018 ◽

Vol 2 (2) ◽

pp. 8

Author(s):

Sugeng Dwi Hartantyo ◽

Rasiyo Hepiyanto

Keyword(s):

Asphalt Concrete ◽

Water Hyacinth ◽

Heavy Traffic ◽

Asphalt Mixture ◽

Cellulose Fiber ◽

Fine Aggregate ◽

Traffic Loads ◽

Marshall Test ◽

Technical Specifications

Laston is a mixture of coarse aggregate, fine aggregate, and filler with a binder under the temperature of 145-155oC with the composition being studied and regulated by technical specifications. Laston is also known as AC (Asphalt Concrete).Laston itself is commonly used in Indonesia with continuous gradations used for heavy traffic loads. To get the addictive material is not easy and the material is expensive. Therefore, it is necessary to find alternatives to the cellulose fiber. Water hyacinth is a water weed that once grow and develop, it has high cellulose fiber content, which is about 60%.For that, done a research to add a hot asphalt mixture material that aims to improve the quality of mixed result. The selected material is natural water hyacinth. The method used is trial and error with reference of SNI 03-1737-1989. Variations used are 3%, 5%, and 7% of the asphalt weight, asphalt level used Is 5.61%.The result of this study is Marshall evaluation where the greatest score obtained for stability is 1325 kg, Flow is 3.73 mm, Quotient Marshall is 401.02 kg/mm, VMA is 66.30%, VFWA is 19.25%, and VIM score is 54.35 %. With this result, the asphalt mixture can not be used because the results of VMA, VFWA, and VIM have not been suitable on specification of SNI 03-1737-1989. Keywords: Laston, Asphalt Concrete, Water Hyacinth, SNI 03-1737-1989.

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Predicting Truck Load Variation Using Q-Truck Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.534.105 ◽

2014 ◽

Vol 534 ◽

pp. 105-110

Author(s):

Rosnawati Buhari ◽

Mohd Ezree Abdullah ◽

Munzilah Md Rohani

Keyword(s):

Asphalt Concrete ◽

Radial Strain ◽

Suspension System ◽

Vehicle Speed ◽

Pavement Distress ◽

Traffic Loads ◽

Road Roughness ◽

Heavy Truck ◽

Truck Load ◽

Pavement Damage

The study of heavy vehicle forces on pavement is important for both vehicle and pavement. Indeed it was identified several factors such as environment, materials and design consideration affects pavement damage over time with traffic loads playing a key role in deterioration. Therefore, this paper presents dynamically varying tire pavement interaction load, thus enable to assess the strain response of pavements influenced by road roughness, truck suspension system, variation of axle loading and vehicle speed. A 100m pavement with good evenness was simulated to check the sensitivity of the dynamic loads and heavy truck vertical motions to the roughness. The most important performance indicators that are required in pavement distress evaluation are radial strain at the bottom of the asphalt concrete and vertical strain at the subgrade surface was predicted using peak influence function approach. The results show that truck speed is the most important variables that interact with truck suspension system and thus effect of loading time are extremely important when calculating the critical.

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