Karaj, a growing city, has roots in Alborz mountains and therefore is faced with challenges such as rockfall which are not typical for cities in Iran. Hafez Square which is a corridor to the city as well as to a major transit road to North of Iran (Chalous Road) is located in the mountain area. As a corridor, it is a major stop to public transportation and private cars. Many tourists also start their travel plans to the Caspian sea from this square. Over the years, weathering of the rocks in the mountain have been rising and consequently, rockfalls have happened on the road. Due to cars and buses stopping in this major square, there have been incidents of rockfall damaging properties and unfortunately, in some cases, fatalities have occurred. The Karaj municipality had to find a solution in order to stop the events from happening. The consultant got involved and performed geotechnical studies as well as rockfall simulations in order to find an optimal solution.
The consultant got involved with the project and asked Geotech to provide its expertise for this phase. Based on prior rockfall incidents, the current topography of the slope, and scanning of boulders in different areas, design boulder was chosen. The rough area to be protected was 700 meters and after final analysis, it was divided into three barrier lines totaling 640 meters. An energy classification of 2000 kJ and a barrier height of 5 meters were selected. Thie installation was performed in two phases - in a total time of 9 months for the entire area. Grouting of the anchors was a challenge due to the cold weather conditions in the winter time but with proper planning, the entire project was finished ahead of schedule.