Writers : Salehi,Fahimeh;Ghafoori, Mohammad; Lashkaripour, Golamreza;Hafezi Moghadas, Naser
Refference : The first international applied geological congress; Department of geology Islamic azad university- Mashhad
Publishing Year : 2010

Abstract :

Mashhad city has been developed in recent decades. The development of the city towards the routes used to be qanat well is one of the problems that Mashhad city is confronted. Today many of the qanats are under urban areas. These qanats become dry little by little because of successive droughts, developing of the city and drilling deep wells In order to supply water. Contemporary of developing the city, the qanats are filled with earth fill soils uncontrollably and this problem causes ground settlement, cracks and fissures in the ground and consequently damages of buildings and also cracking in the system of water supply. This problem is doubled in west areas of the city because of high buildings and high abundance of qanats in those areas. This paper deals with the main factors that cause qanat collapse. First of all the exact location of the qanats in the zone11 of municipality of Mashhad was studied. Then the main factors that influence the stability and performance of qanats were determined. These factors include: depth of qanat gallery, loading due to surface structures, land use, underground water table and geotechnical properties of the soil. Finally areas with the most potential of collapse hazard are introduced. The results can be used in planning for increasing the security level of buildings and structures in hazardous areas of the city.

Subject List : Collapse risk