Vietnam Responding Voters Tender

On 992020 the Ministry of Transport issued Document No. 8941 BGTVT-KCHT to the National Assembly delegation of Phu Tho province regarding the response to voters proposals sent after the 9th session the 14th National Assembly.Specifically the Ministry of Transport received recommendations from voters in Phu Tho province sent by the Board of Volunteers in accordance with Official Letter 288 BDN dated 2472020 the content of the recommendations is as follows The voters of Doan Hung district Phu Tho province reflect Currently Doan Hung bridge on Highway 2 the section across Chay river in Doan Hung town Chi Dam commune has deteriorated and seriously damaged. Therefore from February 2020 Doan Hung bridge is set up with a height of 2.1m so only cars with less than 7 seats motorbikes and rudimentary vehicles can participate in the bridge This has a great impact on the transportation of goods and traffic of people when passing here causing great losses for many businesses. Voters wish to have an early and fast construction plan in the coming time to serve the socio-economic development and goods trade of the people .First of all the Ministry of Transport would like to thank the voters and the delegation of the National Assembly of Phu Tho province for their attention and suggestions on the management and investment in the development of transport infrastructure in the province. Phu Tho aims to help the ministrys state management become better and better meeting the needs of society and people. Regarding the voter petition mentioned above the Ministry of Transport would like to answer as follows Regarding the damaged status of Doan Hung bridge Doan Hung bridge is located on NH2 built in 1984 with a 5-span reinforced concrete girder structure with aperture of 24m span located on 2 abutments M0 on the shore of Phu Tho M5 on the shore of Tuyen Quang 4 pillars from Phu Tho side to Tuyen Quang side are T1 T2 T3 and T4 respectively. Initial design of simple reinforced concrete girder spans reinforced concrete abutments on the pile system the reinforced concrete poles on the I300 steel pile system are attached to the natural foundation.For construction in 2004 the bridge girder was connected continuously with 5 spans and used external prestressed cable DUD to continue the girder system. In 2010 and 2013 a number of parts were repaired and reinforced such as anti-erosion for bridge piers riverbank reinforcement to prevent erosion T2 and T3 piers located on the main stream before deep erosion about 5- 6m should have repaired and strengthened 4 bored piles pillars and expanded the foundation. After a long time of exploitation the work has shown signs of deterioration. The current damages include The T1 column has the heart position horizontal on the top of the pillar deviated from the base of the body about 6cm T3 column has heart at the top of abutment laterally about 15 cm from the heart of pier body at abutment base The elevation of the riverbed continues to be deeply eroded compared to 2013 especially at the position of the T3 pillar which eroded deeper than in 2013 is 7m resulting in the gap of the height of the piles from the base to the river bottom is greater than 11m. very poor pile stability. The beam spans are displaced vertically towards abutment M0 resulting in 2 halves of the expansion joints on the top of the abutment being pressed together the beam head collides with the abutment top wall causing cracking of the top wall the girder spans also tend to move horizontally and on the bridge surface there is a concave span T3 pier area. There are other phenomena on the abutments and pillars apart from cracking of the abutment end wall M0 especially rubber bearings at many positions have now moved vertical horizontal diagonal from the original design position with bearings teleported quite out of position. On the other hand rubber bearings exploited for many years have flattened and parts are removed. Therefore there is a position where the bearing cannot be supported on the beam the position of the bearing is different from the design of the beam and other problems. The work has been exploited for 36 years the exploitation process has been damaged and degraded over time Initially designed the bridge with low load then repaired the 5-span continuous connection and strengthened the girder structure with the outside but not reinforced the abutments The tall thin pillar structure the I300 steel foundation pile system which is attached to the natural foundation cannot resist deep erosion due to the location of the bridges construction with fast flowing and curved rivers large water flow every time Thac Ba Hydropower water discharge besides the narrow and deep river the upstream and downstream sand exploitation also affects the riverbed erosion affecting the bridge abutment structure. The abutments M0 M5 are located quite high the river bank is steep so soil pressure on the abutment cone and after the abutment affects the abutments and T1 piers located near the abutment.