การตรวจสอบสภาพเขื่อนแควน้อย กรณีน้ำไหลผ่านตัวเขื่อนในระหว่างการก่อสร้าง

Abstract

EVALUATION OF KWAE NOI DAM IN FLOW THROUGH CASE DURING CONSTRUCTION

Kwae Noi Dam is a concrete faced rockfill dam (CFRD) situated on the Kwae Noi River in Wat Bot District, Phitsanulok Province. It is 75 m wide and 570 m long. During construction in flood season in 2007, the water overflowed the coffer dam and flowed through Kwae Noi dam which was under the rockfill compaction without concrete face slab. The different head of the upstream and downstream is about 21 m. At that moment, the dam was evaluated that it was safe. It was also expected that if there was flow through the dam in the following year (2008), the different head of the upstream and downstream might rise to 46.50 m. As a consequence, the dam would not be safe. However, it was suggested that the cushion layer and concrete face slab be constructed. The construction had been completed before the flood occurred. Kwae Noi Dam was completed in 2009. Therefore, water was stored almost to its full capacity in 2009 and 2010. Following the preliminary evaluation of the dam, nothing unusual was found due to the water flow through the dam.