The Influence of Groundwater Level on the Structural Behaviour of a Pavement Structure Using FWD

Download
Farhad Salour

The effect of groundwater table level on the structural response of an instrumented flexible pavement in southern Sweden was studied using multilevel Falling Weight Deflectometer (FWD) testing. In order to raise the groundwater table level under the pavement structure, the outlets of the pavement’s subsurface drainage system was blocked for three months. Thereafter, it was unblocked, allowing the pavement to recover to its normal draining condition. During this period, variations in the groundwater level and subsurface volumetric moisture content were registered. Manipulation of the drainage system significantly affected the ground water level and the pavement unbound layers moisture conditions. Both the granular layer and the subgrade stiffness significantly decreased with increasing moisture content. In all the FWDs performed, the granular materials exhibited stress-hardening behaviour. However, the subgrade showed stress-softening response in unsaturated condition and stress-independent behaviour in saturated state. In an attempt to determine the k-theta model parameters from the backcalculated internal stresses and unboundlayers moduli, it was observed that the k1 parameter decreased with increasing moisture content for both the granular layer and the unsaturated subgrade materials.

LATEST NEWS


2018-06-13

International Conference on Electric Road Systems starts today

Electric Road Systems (ERS) is a relatively new concept with many initiatives on the way. To learn from each other and stimulate new collaborations the Swedish Research and Innovation Platform for Electric Roads arranged the first international conference...


2018-05-18

Same survey of road users’ attitudes in 50 countries

At the Road Safety on Five Continents Conference, RS5C, one entire session presented a large survey of road users' attitudes in 38 countries. Results show large differences between countries in many areas, both regarding behavior and attitudes. A new survey...


2018-05-17

Good results with alcohol interlock program according to Swedish study

An alcohol interlock program makes it possible for drink driving offenders to continue their everyday lives. In a Swedish study most of the participants were satisfied with the program and experienced improved health. They also reported drinking alcohol more...


2018-05-16

Traffic safety in the spotlight

Today the Conference Road Safety on Five Continents (RS5C) opened in Jeju Island, South Korea. More than 220 participators have come from all over the world to present findings and learn about traffic safety. Dr. Young Tae Kim, Secretary-General of the...


2018-04-17

VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


2018-04-12

Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...