2. 1950s

(1) 1950 survey

1950 In mid-July, Beijing entrusted the Road Maintenance Engineering Office of the Construction Bureau (hereinafter referred to as the Maintenance Office) to comprehensively maintain the Lugou Bridge and conduct a general survey of the bridge. At that time, the overall situation of Lugou Bridge was relatively complete and the main body was stable. The stone carriage road on the south side of the bridge deck is relatively flat, and the rest is asphalt pavement, which is seriously damaged. Although the stone part of the bridge railing is damaged, it is basically intact. On both sides of Phnom Penh, Fenshuijian and Fenghuang terraces, there are a lot of soil, weeds and small trees.

Two lions are missing.

On June 6th, 1952, 10, tanks passed the Lugou Bridge, and the stone railings between the fourth and fifth sections from the south side of the bridge fell into the river. The people's liberation army picked up a stone, two of which were broken and needed to be rebuilt. Broken fences can be reused with glue. Due to the low level of stone carving technology in the workshop, two sentries were carved according to one column and one lion instead. After bonding and repairing, the remaining stone pieces should be installed and repaired in situ. This time, the number of lions on the post decreased by two, and the total number of lions on the post changed from 488 to 486.

(3) Repair the bridge deck and reduce the slope of the bridge head.

1September 1957 to1June 1958 and1May 1958, the comprehensive technical engineering team of Yanggongyuan carried out two repairs on the main body of Lugou Bridge, mainly smoothing the joints of the whole bridge with cement mortar. In addition to renovating the asphalt pavement on the bridge deck, slope reduction measures have been taken for the bridgehead roads. The road slope at the east and west ends of the bridge is relatively large, and the longitudinal slope of the east bridge is 4.80%. The longitudinal slope of the West Bridge is 4.60%. In order to facilitate the traffic, the bridge deck improvement project of Lugou Bridge was implemented on June 1958. In this construction, the original stone road from the eastern end of the bridge to the west gate of Wanping ancient city was covered under the road. Reduce the road slope to 2? 80%。 The section from the west end of the bridge to Xiaoqing River is a concave pocket. After elevation, granite elastic stone (cubic stone) pavement is laid, and the longitudinal slope is reduced to 2.50%.

(4) Square hole

In the 1 1 holes of the whole bridge, except the sixth, seventh and eighth holes, there are 5 1 square holes in the other eight holes. During the construction, workers filled some square holes in the two walls of bridge opening with cement mortar. Stop it if you find it. The historical reason for the formation of the square cave is: at the end of 19, Xiaoqing River became the overflow diversion channel of Yongding River after the overflow weir was built on the west embankment of the upper reaches of Lugou Bridge. At the beginning of the 20th century, in view of the fact that a large area of fertile land was flooded every year in Xiaoqing River, it was planned to set up simple water conservancy facilities in the hole of Lugou Bridge. Due to the warlords' scuffle and lack of funds, the construction was retired soon. So these square holes were left on the stone wall of the pier. These square holes are historical records and do not affect the safety of the bridge, so they should be kept.

(5) Monuments and pavilions

1950 There are two stone tablets in the east of the bridge, of which the "Lugou Xiaoyue" tablet has a pavilion and the other tablet has no pavilion; There are also two monuments at the western end of the bridge, which are also pavilions and pavilions. The two pavilions are in the same form, both of which are four-column square frame structures with no roof. The northwest pavilion is well preserved and the northeast pavilion is seriously damaged. The stone pillars in the northwest corner did not fall, the stone pillars in the southwest corner fell, and the stone slabs in the west and south collapsed slightly. The fence on the west side fell down. The renovation project of "Lugou Xiaoyue" stele pavilion was completed on June 5438+0950+1October 65438+May 5. Due to lack of funds, the damaged stone in the exhibition hall will be temporarily repaired and installed. 1956 In the spring, it was found that the pavilion of "Lugou Xiaoyue" was damaged again, so it was reported to the municipal government to allocate special funds to completely repair the pavilion of "Lugou Xiaoyue" at the end of September of the same year.

3. 1960- 1970s

Due to the influence of natural disasters and the interference of the "Cultural Revolution", in these 20 years, except the bridge deck widening project, all of them are sporadic maintenance projects.

(1) Bridge deck widening

1In August, 967, the Central "Cultural Revolution Leading Group" ordered the Beijing Revolutionary Committee (municipal government) to solve the problem of poor traffic on the Lugou Bridge. At that time, during the "Cultural Revolution", designers improved the grade of concrete and added more steel bars to prevent poor quality in construction. The engineering practice is to horizontally place 57 long concrete beams on the bridge deck, with both ends suspended outside the bridge. Two pairs (4 concrete short beams) are respectively arranged on the east and west bridge embankments, and their outer ends extend out of the bridge and are laid on the cantilever beam. The original stone railing was moved to the outside of the path. The bridge deck is covered with asphalt.

(2) The even lion.

The former director of the work area and the old engineer are receiving re-education of the working class (taking part in labor), and a young worker is the captain of the construction team. There was an old stonemason from a poor peasant background in the construction team who boldly replaced 9 1 sentry posts and 9 railings by himself. A total of 164 stone lions were carved on 9 1 observation posts. There are five more lions than the original 9 1 sentry post. Make the total number of lions in the whole bridge sentry post reach 49 1. The stone used to replace the railing is taken from the green slate of Taiping Lake wall and No.6 notch material station of municipal engineering management office.

(3) Xinlugou New Bridge.

197 1 year, a new lugou bridge was built about one kilometer away from Beijing lugou ancient bridge. This is a river-crossing highway bridge with a span of 17, with a total length of 54.99m and a width of15.5m..

(4) heightening the retaining wall

1July, 974, according to the notice that the rainstorm area of the National Flood Control Headquarters may move northward, the Yongding River levee was heightened and strengthened. The original protective wall of the swallow wing wall at the east abutment of Lugou Bridge was raised again, so the east wing wall was buried. A stone wall for flood control was built outside the railing of the East Bridge. Six mobile steel column foundations for flood control walls are buried on the east bridge embankment. In June 5438+10 in the same year, asphalt overlay maintenance was carried out on the asphalt surface of bridge deck.

(5) Can pass 400 tons of cars.

1974 dongfanghong refinery (now yanhua petroleum general factory) built an additional 300,000 tons of ethylene plant. In order to make super-heavy vehicles cross the bridge safely,1carried out live load test on Lugou Bridge on October 27th and 28th, 1975+65438. On February 29th, 1976, the super-heavy truck (396 tons) loaded with ethylene glycol reactor passed the Lugou Bridge safely.

4. 1980- 1990s。

(1) The faucet has dropped.

1982 10 found that the faucet on the south chin of the fifth hole in the east fell off, and 49 pieces of missing chin stones were found in the arches of each hole. The fifth hole was badly damaged. 1in April, 1983, the municipal engineering management office (the original maintenance workshop) repaired the granite blocks damaged by the vault with its own funds, totaling 5 1 block. At the same time, repair the faucet that fell off the south chin of the fifth hole.

(2) restore the original appearance

On August 3rd, 1985, another 290-ton large transformer arrived at Dashihe Substation in fangshan county, and six super-heavy vehicles (each with a total weight of 360 tons) passed through Lugou Bridge in turn. After testing, the bridge is still safe and sound. In the same year, a new bridge was built next to Lugou Bridge, and the old Lugou Bridge became a cultural relic and was no longer open to traffic.

1986, launching activities to protect the ancient bridge and restore its original appearance; Make overall plans, mobilize all sectors of society and organize emergency repairs. The project raised 3.55 million yuan. This project demolished 1967 to widen the sidewalk and concrete cantilever beam, and reinforced the original stone fence sentry box; The asphalt was removed and the bridge deck was repaired; At the same time, the ancient city of Wanping was repaired and the tower was restored. And comprehensively improve the pier. All sentry boxes, railings, ground coverings, bridge decks, huabiao, stone tablets, etc. of the ancient bridge are also protected from local weathering and leakage. When the bridge deck is renovated, there is a roof filling in the middle, which completely preserves the original state of the ancient bridge. The reconstruction project of Lugou Bridge adheres to the principle of maintaining the original form, structure and style of Lugou Bridge. All new stones that are replaced will not be regarded as old stones.

1At 4 o'clock in the morning on September 3, 988, thunder broke the No.68 railing sentry from the north side of Lugou Bridge. After 8 o'clock, the person in charge of the project and the person in charge of the Lugouqiao Cultural Relics Protection Institute jointly accepted and handed over the larger gravel to the Lugouqiao Cultural Relics Protection Institute.

The restoration project was completed in February 1990. On 23rd, Shiqiao Office handed over the remaining 6 1 old bridge deck, two old self-faced stones with patterns and several old self-faced stones without patterns, and four old buried stones dug from river bed to.

From June 65438 to June 0997, some stone lions and watchtowers damaged by lightning were repaired and remedied.