Roads are indeed lifelines of economy of a nation. We reach our destination via roads. Goods and other essentials are transported via them. Roads have been in the history since wheels were discovered. With advancement, these have been improved a lot and the journeys made comfortable much. Despite other alternatives being available, roads are still preferred over other means of transport due to its characteristic joy and cost-effectiveness. Roads also connect those distant regions where trains and planes are difficult to reach. Every man-made invention needs maintenance for its proper working. Roads also need maintenance from time to time to check their damage due to aging and weather vagaries; otherwise the ride on damaged roads only bring discomfort and worst memories. In Kashmir valley, due to adverse weather conditions prevalent during most of the year, roads here brave the worst conditions resulting in their early deterioration and ultimately the failure.
Newly laid pavements are seen ruptured immediately after winters due to obvious reasons. But the research and technology advancement in Highway and Geotechnical engineering has some solution for the problems of road if, applied effectively. Alligator cracking, Potholes, Edge cracking and Frost heave are the most common types of road failures prevalent in Kashmir valley. The basic causes of the above failures are either poor drainage or low shearing and bearing strength of sub-grade. However, failure can also occur due to poor quality of pavement materials and improper mix design. The following piece of writing will try to have some understanding about poor drainage and bearing capacity of sub-grade both being the root causes of road failures.
The basic principle that water expands on freezing must be known to all. Small cracks not generally visible to a naked eye are normal in pavements. But with the passage of time, due to wheel load distress and poor drainage of the sub-grade and surrounding soil, variation in shearing and bearing strength develops due to saturation/ over saturation (inundation) of the below layers of the pavement. Slight settlement occurs in the pavement surface widening the minute cracks. These are reflected on the exposed surface of the road as Alligator cracks, Edge cracks and Potholes.
Below freezing point temperature in the winters cause the moisture in these cracks to expand thus implying pressure on the pavement walls leading to further damage to the road. Also, the moisture in saturated sub-grade soil freezes and expands leading to raising of the above pavement layers viz sub-base and base (though very small in magnitude) but this slight rise is reflected as Frost heave on the surface. This Frost heave weakens the adhesion between the pavement layers as well as among the pavement materials leading to degeneration of the roads.
Potholes are the typical road failures which are caused due to joining of Alligator cracks into big lumps which due to vehicle movement disintegrates resulting in a bowl shaped depressions having depth up to sub-base level with vertical sides. During precipitation, these get filled with water posing a grave threat to road users. Potholes if not treated timely make the road non-useable. Road failures not only make our journeys uncomfortable but also sometimes cause serious avoidable accidents leading to loss of precious lives.
Apart from these environmental distress failures, roads can also fail due to wrong design. No strict design parameters like camber, super-elevation, proper surface drainage, provision for retardation of capillary rise etc are followed here by the contractors. Proper surface drainage is a must here but either it is ignored at the time of road construction due to paucity of funds or is rendered non-functional (if provided anywhere) by the greedy elements in the society. Furthermore, the concerned executing and superintending agencies do not hold the contractors accountable for the breach in execution of required design standards set forth by them. We saw how the city centre (Lal chowk) was inundated after few hours of rainfall this summer the only reason being the clogging or absence of the surface drainage. This leads to early deterioration of the roads even if, pavement materials are of standard quality and a huge loss to the exchequer.
Nature has given different regions different climate, weather and different environments for which the man has adapted himself in required way. Similarly, in civil engineering, the choice of using materials and design is flexible depending wholly on the requirement. Pavement materials and other design parameters of road in arid region would be very much different than that of cold and wet regions. Same is the case with road infrastructure in Kashmir valley which needs special method of construction and its maintenance.
In all, it is the ill methods of construction that makes roads deteriorate much early than their service life. It is obvious engineering fact that water is poison to the roads because its ability to percolate deep in the pavement layers and changes its physical properties adversely affect the life of the road.
Recently, a comprehensive audit of the city roads of district Srinagar was done. The audit committee constituted engineers and involve over 100 officials and personnel from half a dozen agencies and departments .The committee also found that the early degeneration of roads was due to poor drainage network and problems in designing stage.
Need of the hour is to follow proper Highway and Geo-Technical engineering codes as well as latest research based practices after proper analysis of the environment and conditions of the site at the time of road construction. Proper and timely maintenance in case of minor damages by the concerned agencies is equally important so as to prevent the further damage of the roads. This will not only save the time and resources of Government but also cater to irks and problems of the road users in the long run.
—(Author is studying Geo-Technical Engineering from Kurukshetra University and can be reached at [email protected] )