HORIZONTAL CURVES ARE DESIGNED USING A DESIGN SPEED, WHICH IS THE SPEED USED TO DETERMINE THE GEOMETRIC FEATURES OF HIGHWAYS. IN SHARP CURVES, DRIVERS SOMETIMES EXCEED THE DESIGN SPEED. DEPENDING OF THE DIFFERENCE BETWEEN DESIGN SPEED AND OPERATING SPEED, DRIVERS CAN FACE RISKY SITUATIONS, WHICH CAN BE MITIGATED USING SIGNS INFORMING DRIVERS OF ADVISORY SPEEDS. ADVISORY SPEEDS AT THE HORIZONTAL CURVES ARE NORMALLY ESTIMATED AS A FUNCTION OF THE LATERAL ACCELERATION FOR A MAXIMUM DRIVING SPEED, AT WHICH COMFORT IS LOW. THIS PAPER PROPOSES AN ANALYTICAL MODEL TO ESTIMATE ADVISORY SPEEDS BASED ON BALL-BANK READINGS AND CONSISTENCY CONCEPTS. FIELD DATA WERE OBTAINED USING A DIGITAL BALL-BANK INDICATOR, AN ACCELEROMETER, AND A GPS LOGGER. READINGS WERE OBTAINED ON 24 TEST SECTIONS AT SPEEDS BETWEEN 40 AND 110 KM/H. THE MODEL PROPOSED YIELDS AN ADVISORY SPEED VALUE AND A LIMIT BALL-BANK ANGLE THAT REQUIRE CONSISTENT BEHAVIOR OF DRIVERS.

LA REDUCCIÓN DE LA VELOCIDAD DEL CAMIÓN EN PENDIENTES ASCENDENTES AUMENTA EL RIESGO DE ACCIDENTE. LOS MODELOS DE VELOCIDAD-DISTANCIA EXISTENTES ESTIMAN LA REDUCCIÓN DE VELOCIDAD EN PENDIENTES ASCENDENTES ASUMIENDO QUE LAS FUERZAS RESISTIVAS SON IGUALES A LAS FUERZAS DE TRACCIÓN. EN ESTE CASO, LA VELOCIDAD DEL CAMIÓN ES MÍNIMA Y SE DENOMINA VELOCIDAD DE ARRASTRE. ESTE ARTÍCULO DESCRIBE LA CALIBRACIÓN DE UN MODELO DE VELOCIDAD-DISTANCIA EN PENDIENTES ASCENDENTES CORTAS USANDO DATOS OBTENIDOS CON UN DISPOSITIVO GPS. LA CALIBRACIÓN SE REALIZÓ PARA CAMIONES CON UNA RELACIÓN DE PESO A POTENCIA DE 95-160 KG / KW Y PARA VELOCIDADES DE OPERACIÓN DE 70-93 KM / H AL COMIENZO DE LA PENDIENTE ASCENDENTE. LOS RESULTADOS MUESTRAN QUE EN PENDIENTES CORTAS HACIA ARRIBA, LA VELOCIDAD MÍNIMA FUE DE 1,5 VECES MÁS ALTA QUE LA VELOCIDAD DE RASTREO TEÓRICA. EL MODELO TAMBIÉN SE UTILIZÓ PARA OBTENER LA LONGITUD REQUERIDA PARA UNA REDUCCIÓN DE VELOCIDAD DE 15-40 KM / H

NATURAL DISASTERS SUCH AS EARTHQUAKES AND TSUNAMIS FOSTER THE CREATION OF EFFECTIVE EVACUATION STRATEGIES TO PREVENT THE LOSS OF HUMAN LIVES. THIS ARTICLE PROPOSES A SIMULATION MODEL TO FIND OUT OPTIMUM EVACUATION ROUTES, DURING A TSUNAMI USING ANT COLONY OPTIMIZATION (ACO) ALGORITHMS. ACO IS A DISCRETE OPTIMIZATION ALGORITHM INSPIRED BY THE ABILITY OF ANTS TO ESTABLISH THE SHORTEST PATH FROM THEIR NEST TO A FOOD SOURCE, AND VICE VERSA, USING PHEROMONES. THE VALIDATION OF THE MODEL WAS CARRIED OUT THROUGH TWO DRILLS, WHICH WERE CONDUCTED IN THE COASTAL TOWN OF PENCO, CHILE. THIS TOWN WAS STRONGLY AFFECTED BY AN 8.8 MW EARTHQUAKE AND TSUNAMI OVER FEBRUARY 2010. THE FIRST DRILL WAS HELD WITH MINIMUM INFORMATION, LEAVING THE POPULATION TO ACT RANDOMLY AND INTUITIVELY. THE SECOND DRILL WAS CARRIED OUT WITH INFORMATION PROVIDED BY THE MODEL, INDUCING PEOPLE TO USE THE OPTIMIZED ROUTES GENERATED BY THE ACO ALGORITHM. THE RESULTS SHOWED THAT, IN CASE OF AN EMERGENCY, CONVENTIONAL EVACUATION ROUTES SHOWED LONGER ESCAPE TIMES COMPARED TO THOSE PRODUCED BY THE MODEL DEVELOPED IN THIS RESEARCH.

THE PAVEMENTS OF CONCRETE PAVERS (PAH) ARE USED AS AN ALTERNATIVE TO TRADITIONAL PAVING OF LOW SPEED DRIVEWAYS. THIS PAPER ANALYZE THE PAH DESIGN METHODS PROPOSED IN AUSTRALIA, JAPAN, UNITED STATES, UNITED KINGDOM AND INDIA. A RANGE OF CBR SUBGRADE BETWEEN 4% AND 20% AND TRAFFIC LEVELS BETWEEN 45,000 AND 4,500,000 CUMULATIVE EQUIVALENT AXLES WERE USED. THE PERFORMANCE PARAMETERS FOR DESIGN WERE THE STRESSES, STRAINS AND DEFLECTIONS OF THE SUBGRADE, WHICH WERE COMPARED WITH ALLOWABLE VALUES. RESULTS SHOWED THAT FOR CBR> 10% AND LOW TRAFFIC LEVELS, ALL DESIGNS CONVERGED TO A MINIMUM DESIGN AND ALSO ACCOMPLISHED WITH THE 3 PERFORMANCE PARAMETERS USED IN THIS RESEARCH. IT WAS DETERMINED THAT HIGHER LEVELS OF TRAFFIC AND CBR

THE PAVEMENTS OF CONCRETE PAVERS (PAH) ARE USED AS AN ALTERNATIVE TO TRADITIONAL PAVING OF LOW SPEED DRIVEWAYS. THIS PAPER ANALYZE THE PAH DESIGN METHODS PROPOSED IN AUSTRALIA, JAPAN, UNITED STATES, UNITED KINGDOM AND INDIA. A RANGE OF CBR SUBGRADE BETWEEN 4% AND 20% AND TRAFFIC LEVELS BETWEEN 45,000 AND 4,500,000 CUMULATIVE EQUIVALENT AXLES WERE USED. THE PERFORMANCE PARAMETERS FOR DESIGN WERE THE STRESSES, STRAINS AND DEFLECTIONS OF THE SUBGRADE, WHICH WERE COMPARED WITH ALLOWABLE VALUES. RESULTS SHOWED THAT FOR CBR> 10% AND LOW TRAFFIC LEVELS, ALL DESIGNS CONVERGED TO A MINIMUM DESIGN AND ALSO ACCOMPLISHED WITH THE 3 PERFORMANCE PARAMETERS USED IN THIS RESEARCH. IT WAS DETERMINED THAT HIGHER LEVELS OF TRAFFIC AND CBR

IN RECENT YEARS A DISCUSSION OF THE TECHNICAL-ECONOMIC FEASIBILITY OF INTRODUCE THE HEAVY LOAD TRUCKS (CAT) IN GOODS TRANSPORT FLEET WAS STARTED. THIS TRUCK CONFIGURATIONS OVERPASS THE MAXIMUM GROSS WEIGHT OF 45 T PERMITTED IN CHILE. IN CHILE THERE NOT EXIST EXPERIENCE OF USING THIS TYPE OF TRUCKS, WHENCE IS RELEVANT TO STUDY THE GLOBAL IMPACT OF IT OVER THE INTERURBAN TRANSPORT SYSTEM. THIS PAPER DISCUSSES THE IMPACT OF HEAVY LOAD TRUCKS OVER ASPHALT PAVEMENTS. USING A MECHANISTIC-EMPIRICAL FRAMEWORK, THE IMPACT OF TWO TYPES OF CAT, LONG AND SHORT BITRÉN, AND A ONE AND TWO UNITS 45 TONS TRUCKS WERE COMPARED ALONG THE LIFE-CYCLE OF THE PAVEMENT.......

THE OPERATING SPEED VARIATION IN HORIZONTAL REVERSE CURVES IS A PROBLEM OF RELEVANCE TO ROAD SAFETY. IF THE SPEED VARIATIONS ARE HIGH AND THE TANGENT BETWEEN THE CURVES IS SHORT, THEN THE CRASH RISK INCREASES. THE OPERATING SPEED CAN BE PREDICTED USING OPERATING SPEED PROFILE MODELS THAT CORRELATE THE OPERATING SPEED WITH THE RADII AND TANGENTS OF THE HORIZONTAL REVERSE CURVES. THIS STUDY PROPOSES A NEW OPERATING SPEED MODEL FOR HORIZONTAL REVERSE CURVES USING SPEED DATA OBTAINED WITH A 10 HZ GLOBAL POSITIONING SYSTEM LOGGER. SPEED, HEADING AND POSITION DATA WERE COLLECTED FOR 30 RUNS PER SITE AT 34 TEST SITES. TANGENT LENGTHS, DEFLECTIONS, CURVE LENGTHS AND RADII WERE ALSO OBTAINED. THE OPERATING SPEED MODELS WERE CALIBRATED USING EIGHT POINTS ALONG THE REVERSE CURVES MEASURED. THE STANDARD ERRORS OBTAINED IN THE SELECTED MODELS RANGED BETWEEN 3·0 AND 6·6 KM/H, THE ROOT MEAN SQUARE ERROR RANGED FROM 0·6 TO 2·7 KM/H, AND THE R2 VALUE OF INDIVIDUAL SPEED?GEOMETRY MODELS VARIED BETWEEN 0·52 AND 0·99. THE MODELS OBTAINED ALLOWED ENGINEERS TO ASCERTAIN THE OPERATING SPEED PROFILE AT THE HORIZONTAL REVERSE CURVE AND TO STUDY THE EFFECTS OF DIFFERENT DESIGN ALTERNATIVES ON THE OPERATING SPEED.

DESPITE ALL EXISTING INFORMATION ABOUT THE FACTORS THAT COULD DEFINE A ROLE FOR THE CIVIL ENGINEER OF THE CONTEMPORARY CHILEAN SOCIETY, THERE IS LIMITED EVIDENCE OF A STUDY THAT INTEGRATES ALL THESE FACTORS, THROUGH A MODEL THAT ALLOWS DEFINING THIS ROLE BY USING A QUALITATIVE AND QUANTITATIVE ANALYSIS. THIS PAPER PRESENTS THE RESULTS OBTAINED FROM THE ANALYSIS OF THE ROLE OF THE CIVIL ENGINEER IN THE CONTEMPORARY CHILEAN SOCIETY, PARTICULARLY SINCE THE CREATION OF THE CHILEAN ECONOMIC DEVELOPMENT AGENCY (CORFO) IN 1939, UNTIL TODAY. THE STUDY FOCUSES ON OBTAINING INFORMATION THROUGH A COMPREHENSIVE LITERATURE REVIEW, ALONG WITH THE APPLICATION OF AN ASSESSMENT INSTRUMENT (INTERVIEW), TO SOME OF THE MOST PRESTIGIOUS CIVIL ENGINEERS IN CHILE, BOTH PROFESSORS AND/OR PROFESSIONALS; INFORMATION THAT WAS THEN PROCESSED AND ANALYZED BY USING STRUCTURAL EQUATION MODELING (SEM). THIS ALLOWED ESTABLISHING SOME OF THE PARAMETERS THAT BEST DEFINE THE ROLE OF THE CONTEMPORARY CIVIL ENGINEER IN CHILE, NAMELY: ACADEMIC BACKGROUND, PROFESSIONAL PERFORMANCE, LEADERSHIP, INNOVATION AND, CONNECTION WITH SOCIETY . QUANTITATIVE ANALYSIS OF THESE PARAMETERS WAS PERFORMED BY MEANS OF STRUCTURAL EQUATION MODELING, PARTICULARLY THROUGH THE USE OF PARTIAL LEAST SQUARE (PLS). IN ORDER TO COMPLEMENT AND STRENGTHEN THE QUANTITATIVE ANALYSIS, A QUALITATIVE ANALYSIS WAS ALSO PERFORMED, THROUGH THE TECHNIQUE OF PATTERN-MATCHING. THUS, IT WAS POSSIBLE TO BUILD AND VALIDATE A MODEL THAT WOULD CHARACTERIZE THE FUNCTIONS OF THE CONTEMPORARY CIVIL ENGINEER, BASED ON THE AFOREMENTIONED PARAMETERS, CONCLUDING THAT THE ROLE OF THIS PROFESSIONAL, IN THE CONTEMPORARY CHILEAN SOCIETY, IS BASED ON HER/HIS ACADEMIC BACKGROUND, THE CREATIVITY AND INGENUITY THAT HAS TO PROVIDE INNOVATIVE SOLUTIONS, THROUGH AN EXCELLENT PROFESSIONAL PERFORMANCE, AND TAKING INTO ACCOUNT THE WELFARE OF THE ENVIRONMENT WHERE SHE/HE WORKS.

SUPERVISION DURING THE EXECUTION PHASE OF A CONSTRUCTION PROJECT IS ESSENTIAL TO ENSURE SUCCESSFUL PROJECT COMPLETION. IN MOST INSTANCES, THIS TASK IS COMPLETED BY QUALIFIED TECHNICAL AUTHORITIES, ALSO KNOWN AS OWNER?S REPRESENTATIVES (ORS). THIS RESEARCH PRESENTS A MODEL TO ANALYZE THE ROLE OF THE OR DURING THE EXECUTION PHASE OF CONSTRUCTION PROJECTS USING A MULTIVARIABLE?PARTIAL LEAST SQUARES (PLS)?ANALYSIS. THIS ANALYSIS WAS USED TO DETERMINE THE INTERRELATION OF OR ACTIVITIES THAT PERTAIN TO PROJECT SUCCESS. A PLS MODEL WAS DESIGNED TO ASSESS THE SIGNIFICANT FACTORS THAT INFLUENCE THE EFFECTIVENESS OF OR OPERATIONS USING THE DATA GATHERED THROUGH SURVEYS DISTRIBUTED TO MANAGERS OF CONSULTING FIRMS THAT PROVIDE OR SERVICES IN CHILE. THE PLS MODEL RESULTS INDICATED THAT THE MOST IMPORTANT ACTIVITIES FULFILLED BY THE ORS ARE QUALITY CONTROL, COST CONTROL, SCHEDULE TRACKING (TIME), OWNER/CONTRACTOR RELATIONS, AND PRODUCTIVITY VERIFICATION. ALTHOUGH THE FIRST THREE ARE GENERALLY ACCEPTED TO BE THE FUNDAMENTAL ELEMENTS OF A SUCCESSFUL PROJECT, FINDINGS PRESENTED HERE PROVIDE ADDITIONAL INSIGHT, QUANTITATIVE ASSESSMENT OF ALL THESE FACTORS, THEIR INTERRELATIONS, AND THE STRENGTH OF THESE RELATIONSHIPS. THIS ARTICLE IS CONCLUDED WITH PRACTICAL IMPLICATIONS OF THE FINDINGS THAT WOULD ENABLE MORE EFFICIENT CONSTRUCTION PROJECT MANAGEMENT.

TRADITIONALLY, THE GEOMETRIC DESIGN OF HORIZONTAL CURVES HAS BEEN PERFORMED IN ACCORDANCE WITH THE POINT MASS MODEL IN THE MAJORITY OF DESIGN REGULATIONS. HOWEVER, WE MAY ASK OURSELVES WHETHER THE TRADITIONAL DESIGN APPROACH CONTRIBUTES TO ROAD SAFETY. RESEARCH UNDERTAKEN IN AUSTRALIA, UNITED STATES AND CHILE HAS SHOWN THAT IN ROAD DESIGNS WITH AVERAGE AND LOW CATEGORIES THE SPEED OF OPERATION EXCEEDS THE SPEED OF DESIGN IN HORIZONTAL CURVES. GIVEN THIS FACT, WE ASK OURSELVES WHICH IS THE REAL SAFETY MARGIN OFFERED BY THE DESIGN OF THE CURVE AND HOW IS IT POSSIBLE TO ESTIMATE IT. IN THIS PAPER THE AUTHORS PROPOSE A NEW DESIGN APPROACH BASED ON THE 3-ZONE MODEL, WHICH INTEGRATES CONCEPTS OF FRICTION DEMAND, DESIGN FRICTION, REAL ROAD SURFACE FRICTION AND FRICTION THRESHOLDS IN THE DESIGN OF HORIZONTAL CURVES. THIS INTEGRATION IS PERFORMED UNDER A PROBABILISTIC APPROACH BASED ON THE RELIABILITY THEORY, WHICH ALLOWS US TO ESTIMATE THE SAFETY MARGIN OFFERED BY VARIOUS DESIGNS, RECOGNISING THAT THE SPEED OF OPERATION AND THE FRICTION ARE RANDOM VARIABLES, THUS EXPANDING THE SAFETY FACTOR CONCEPT TRADITIONALLY UTILISED IN ENGINEERING. THIS PAPER DEVELOPS THE CONCEPTS OF RELIABILITY AND THE WAY IN WHICH THEY ARE APPLIED IN THE 3-ZONE MODEL. THROUGH SIMULATION, WE OBTAIN THE RELATIONS BETWEEN THE GEOMETRY AND THE POINT IN THE DESIGN THAT MAXIMISES ITS RELIABILITY. FINALLY, WE PERFORM AN APPLICATION TO ILLUSTRATE THE METHOD DEVELOPED, CONSTITUTING AN ALTERNATIVE TO TRADITIONAL DESIGN METHODS THAT DELIVERS MORE CONCEPTUAL ELEMENTS THAT FOSTER AN ENHANCED DESIGN ANALYSIS.