Browsing by Author "Gunarathna, WPH"

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item: Conference-Abstract
Finite element model analysis to determine improved support condition for concrete block paved low volume roads
(Department of Civil Engineering, University of Moratuwa., 2010) Gunarathna, WPH; Mampearachchi, WK; Pasindu, HR
The intensive process of urbanization in the last century has caused a need for rapid construction of roads and related infrastructure in Sri Lanka. The rapid demand for better roads and services required the designers and the builders to introduce suitable construction methods in order to economize the construction as well as increase the durability. In Sri Lanka, large percentage of low volume roads has been constructed using gravel, concrete or bitumen as the primary material. Due to lack of maintenance of the roads in rural sector, Engineers are trying to find alternative cost effective pavement construction techniques. Concrete block paving (CBP) is one of the predominant road construction methods used in most of the developing counties due to economic adaptability. This method can be emerged as a cost effective road construction method suitable for different ground conditions with low life cycle cost. However, this technique yet to be developed to a fully fledge road construction method in Sri Lanka. Therefore, standard set of guide lines are needed to maintain consistency and construction quality of block paving technology. The aim of this research is to evaluate the state of support conditions for low volume roads and effective block laying patterns which can be used to obtained best performance from concrete block paving. Therefore verified three-dimensional (3-D) finite element model (using SAP2000 structural analysis software) was used to measure elastic deflection behavior of concrete block pavement for low volume roads. Developed design chart can be used for subgrade improvements for low volume roads condition and find best laying arrangement in the concrete block paving to obtain most excellent interlocking action.
item: Thesis-Abstract
Finite element model approach to determine an effective layout and suppport conditions for concrete block paving
Gunarathna, WPH; Kumara, MAW
There has been an intensive process of urbanization which has brought about need for rapid construction of roads and related infrastructure during the end of the last century. Therefore development of economical road construction methods is a high priority for a developing country like Sri Lanka. Concrete block paving is one of the predominant road construction method used in most of the developing counties due to economic adaptability. This method has also been emerged as a cost effective road construction method suitable for certain local conditions. But in Sri Lanka this technique is yet to be developed to a fully fledge road construction method. This can be attributed to a dearth of the technical expertise and knowledge. As a result, there is a great need to develop knowledge and establish proper methods of block paving suitable for local conditions. The aim of this research is to evaluate the state of support conditions and effective block laying patterns which can be used to improve concrete block paving technology. Prototype concrete block paving model development, support conditions and their improvements were mainly considered in the development stage of this study. Laboratory scale prototype concrete block pavement model was developed and their surface deflection basin was measured with four different arrangements. A three dimensional (3-D) finite element model was developed to measure elastic deflection behavior of concrete block pavement ,with SAP2000 structural analysis software. This Finite Element Model (FEM) was used to simulate field conditions of a concrete block pavement and it was verified with the deflection values observed in the prototype model. The verified software model was used to perform a parametric study in order to determine necessary improvements for weaker support conditions and find effective laying arrangement in the concrete block paving. . Developed design charts and field observations are used to propose subgrade improvement methods for weaker support conditions. Therefore it's recommended' to introduce concrete block laying work for low volume roads which are having subgrade strength higher than 10% (CBR). FEMs were developed to evaluate performance of the laying patterns. Four different block laying patterns were tested against breaking action and vertical loading. Finally it was possible to conclude that herring bond pattern is more suitable for road construction work with better performance.
item: Article-Full-text
Finite-element model approach to determine support conditions and effective layout for concrete block paving
(American Society of Civil Engineers, 2010) Mampearachchi, WK; Gunarathna, WPH
Concrete block paving CBP is one of the predominant road construction methods used in most of the developing counties due to its economic adaptability. It has emerged as a cost-effective road construction method suitable for different ground conditions but this has yet to be developed as a full fledged technique because of the dearth of technical expertise and knowledge. The aim of this research is to evaluate the state of support conditions and to discover effective patterns which can be used to improve concrete block paving technology. Development of a laboratory scale CBP model and evaluation of support conditions were mainly considered in the initial stage of this study. A developed laboratory scale CBP model was used to measure deflection basin with four different load arrangements. A three-dimensional finite-element model was built to measure elastic deflection behavior of concrete block pavement with SAP2000 structural analysis software. This finite-element model was used to simulate field conditions of a concrete block pavement and it was verified with the deflection values observed in a laboratory scale model. The verified analytical model has been used to perform a parametric study in order to determine necessary improvements for weaker support conditions and find effective laying arrangement in the concrete block paving. Developed design charts and field observations can be used to propose subgrade improvement methods for weaker support conditions. The writers recommend concrete block laying work for low volume roads with subgrade strength higher than 10% CBR. The results indicate that herringbone bond pattern performed well under effect of vertical loading and breaking action. It has the capability to develop better interlocking action in CBP work.