Regressive approach for predicting bearing capacity of bored piles from cone penetration test data

In this study, th e least sq u are su p p o rt v ecto r m achine （LSSVM） alg o rith m w as applied to predicting th ebearing capacity o f b ored piles e m b ed d ed in sand an d m ixed soils. Pile g eo m etry an d cone p e n e tra tio nte s t （CPT） resu lts w ere used as in p u t variables for pred ictio n o f pile bearin g capacity. The d ata u se d w erecollected from th e existing litera tu re an d consisted o f 50 case records. The application o f LSSVM w ascarried o u t by dividing th e d ata into th re e se ts： a train in g se t for learning th e pro b lem an d obtain in g arelationship b e tw e e n in p u t variables an d pile bearin g capacity, and testin g an d validation sets forevaluation o f th e predictive an d g en eralization ability o f th e o b tain ed relationship. The predictions o f pilebearing capacity by LSSVM w ere evaluated by com paring w ith ex p erim en tal d ata an d w ith th o se bytrad itio n al CPT-based m eth o d s and th e gene ex pression pro g ram m in g （GEP） m odel. It w as found th a t th eLSSVM perform s w ell w ith coefficient o f d eterm in atio n , m ean, an d sta n d ard dev iatio n equivalent to 0.99,1.03, an d 0.08, respectively, for th e testin g set, an d 1, 1.04, an d 0.11, respectively, for th e v alidation set. Thelow values o f th e calculated m ean squared e rro r an d m ean ab so lu te e rro r indicated th a t th e LSSVM w asaccurate in p redicting th e pile bearing capacity. The results o f com parison also show ed th a t th e p roposedalg o rith m p red icted th e pile bearin g capacity m ore accurately th a n th e trad itio n al m eth o d s including th eGEP m odel.

Effective Use of Cement for Modification of Base Course Material

Cement improves properties of soil materials, such as durability, stiffness, strength and moisture susceptibility. Each of them needs different cement contents that might not be suitable for other properties. Typically, high cement content is desirable for durability, but not for shrinkage and cracking issues on the surface. Thus, improving durability with low cement content while complying with other requirements is an ideal aim, which may be achieved by pozzolanic supplementary products. Pozzolans contribute in hydration reactions and optimise cement consumptions in favour of durable and low shrinkage products. In this paper, the mixes of nano-silica and fly ash are considered to investigate their effect on strength, durability and shrinkage of modified CRB （crushed rock base） material. In the end, the benefits and features of nano-silica as a pozzolanic material will be focused and discussed more for effective cement consumption in soils.

Comparison of Traffic Growth Factors in Three Major Highways of Bangladesh： A Case Study

The unanticipated increase in vehicle population and heavy axle loads has brought the road network of Bangladesh to a crumbling stage. The network is grossly short of its structural capacity, highly distressed and has started showing signs of premature failure. The RHD （Roads and Highways Department） of Bangladesh uses 8%-10% growth rate of traffic for structural design of these highways that need to be upgraded due to present high traffic volume demand. An attempt has been made through this case study, by using traffic flow data from different computerized toll plaza established in recent times, to predict traffic growth pattern of different highways of Bangladesh. The toll collectors of different computerized toll plaza have been recording and preserving round-the-year continuous flow data in a systematic manner. The study has taken this prospect of utilizing several years of flow data along Dhaka-Chittagong Highway （N-1）, Dhaka-Sylhet Highway （N-2）, Dhaka-North Bengal Highway （N-5） and found the traffic growth factor of 21.03%, 23.79% and 11.31%, respectively, which is much higher than that transport authority of Bangladesh is currently using. By the use of accurate traffic engineering parameters such as traffic growth factors, it is possible to resist frequent distress of pavement and sustainable pavement management can be implemented by RHD.

Examining Attitudes Towards Safe Speed to Protect Pedestrians

Share of night time pedestrian fatalities has been associated with human factors for many years.The focus of the present paper aims to examine the option of introducing 40km/h night zone speed limit.Particularly targeting the 60km/h limit roads to further protect pedestrians.Questionnaires of the study were distributed to a random sample of four groups.Australians(born in Australia)and three others,Australians born in different countries and belongs to Africa,Asia and Europe.The Questionnaires were related to preference of introducing 40km/h during the night(Night Zone)and also related to the delay concerns of introducing 40km/h during the day(Day Zone).The total number of participants in the study is 300 of the four groups.Each group has 75 participants.The study utilized age,gender and marital status as independent variables.Literature search has found different pedestrian fatality trends of the four cultural groups some are ascending and the others are descending.Therefore the study hypotheses that cultural groups living in Perth are different in terms of their attitudes towards the preference Night Zone and the delay concerns of the Day Zone.Acceptance of the Night Zone preference reached 64%whereas;the mean rate responses reached 74%for the Day Zone delay concerns.It was learned from results that attitudes differences existed between the cultural groups on both Night Zone and Day Zone options as hypothesised.Result showed that Asian group recorded the lowest rate for the Night Zone preference and cluster analysis depicted that clearly.There was statistically significant difference on drivers obeying the sign limit,between Asian and two groups namely African and Australian.Similarly cluster analysis performed for the Day Zone,indicated that European group was away from the rest of the clustered groups showing less concerns of implementing the Day Zone option on particular issue and that is,“European group do not believe that the delay is caused by the 40km/h speed limit but rather they believe it is due to the traffic signals”.Australian group were the most concern about implementing the Day Zone limit,as they recorded the highest mean rate response 77%.There was statistically significant difference between singles and non-singles on the preference of Night Zone differences.A statistical difference was also found between male drivers who believe that 40km/h during the day is too slow compared to female drivers.The 18-29 years age group was the most concern about the Day Zone implementation compared to other age groups.Surprisingly,they also recorded the lowest mean response rate for the implementation of 40km/h Night Zone limit of all age groups.They reveal their attitudes against implementing of the 40km/h limit all together and preferring to leave the 60km/h speed limit unchanged.Details of Multivariate Analysis of Variance(MANOVA)are included throughout the analysis.Some analysis,results and conclusions of this paper are valuable and useful for practitioners for exposing the ideas of drivers.Knowing that the Arab Gulf Countries particularly the Kingdom of Saudi Arabia is a host to many expatriates who are road users(drivers or pedestrians)contributing to pedestrian fatalities.

Camera System Deployment for Speeding Control in Australia

In Australia,the Auditor-General plays the role of checking on system fiscal efficiency,performance and effective communications between safety professionals and the public road users.The focus of this paper is to evaluate the possibility of public approval of the information that is to be released,e.g.camera strategic initiatives assessed by through mail-out questionnaires.Two visual-and-policy related attributes were investigated in these questionnaires.Each attribute had 5 initiatives.A multi-logistic regression is performed on the approval level of the drivers for the strategic initiative of running a speed-awareness course.This initiative is determined to be statistically significant using independent variables age,years of experience,status,gender,and the driver environment.Our analysis shows that the driver environment/background is found to be a significant independent variable for approving speed awareness courses.The road users from non-industrial areas are more likely to approve the idea of speed awareness courses than road users from industrial areas.They also welcome tougher demerit rules and the police enforcement.Our study suggests the speed awareness course,an educational initiative,should incorporate the tougher demerit rules to change the repetitive offender’s driving behaviour.It is foreseeable that once these drivers are enrolled into the course,safer driving practices would be achieved for mitigating dangers,risk and trauma as the result of speeding.Our study may benefit professionals involved with improving traffic safety such as those in Asia,Africa,the Middle East and the Arab gulf countries particularly the kingdom of Saudi Arabia where a high number of fatalities and serious injuries involved speeding.Our study confirms that positive,transparent and satisfying initiative should be executed with care to maintain sustainable and safer roads for enhancing national partnership between road users and authorities.

Dynamic analysis of falling weight deflectometer

Falling weight deflectometer （FWD） testing has been used to evaluate structural condition of pavements to predict the layer moduli using backcalculation process. However, the predicted pavement layer moduli sometimes may not be accurate even if computed and measured deflection basin has fulfilled the standard and is in concurrence with certain tolerable limits. The characteristics of pavement structure, including pavement layer thickness condition and temperature variation, affect the predicted pavement structural capacity and back calculated layer modulus. The main objective of this study is to analyze the FVc＇D test results of flexible pavement in Western Australia to predict the pavement structural capacity. Collected data includes, in addition to FWD measurements, core data and pavement distress surveys. Results showed that the dynamic analysis of falling weight deflectometer test and prediction for the strength of character of flexible pavement layer moduli have been achieved, and algorithms for interpretation of the deflection basin have been improved. The variations of moduli of all layers along the length of sections for majority of the projects are accurate and consistent with measured and computed pre- diction. However, some of the projects had some inconsistent with modulus values along the length of the sections. Results are reasonable but consideration should be taken to fix varied pavement layers moduli sections.

Performances of hydrated cement treated crushed rock base for Western Australian roads

The resilient modulus （RM） of hydrated cement treated crushed rock base （HCTCRB） affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The related trends of RM corresponding to the different hydration periods still cannot be concluded. Instead, It is found that the moisture content plays more major influence on the RM performance. Higher additional water during compaction of HCTCRB, even at its optimum moisture content and induced higher dry density, led to the inferior RM performance compared to the sample without water addition. The RM of damper samples can be improved through dryback process and superior to that of the sample without water addition at the same moisture content. However, the samples withut water addition during compaction deliver the comparable RM values even its dry density is lower than the other two types. These results indicate the significant influence of moisture content to the performances of HCTCRB with regardless of the dry density. Finally, the experimental results of HCT- CRB and parent material are evaluated with the K-O model and the model recommended by Austroads. These two models provide the excellent fit of the tested results with high degree of determination.

Performance of fiber reinforced clayey sand composite

Soils and their related behavior have always been the subject of many studies.Recent researches show some interests in investigation of inclusion of randomly distributed fiber in soil.This study focuses on effect of fiber inclusion on the strength and other parameters of clayey sand composite material.First part of this study is related to effective parameters on strength of the clayey sand composite with using natural fiber and plastic fiber and different fiber contents and length.Triaxial consolidated undrained(CU)tests were carried out to investigate behavior of the composite under different condition.The fiber percentage varied from 0%(for unreinforced samples)to 4%and fiber length varied from 8 to 25 mm.The fiber length and fiber content found to play important rule on the strength of fiber reinforced composite.