Xiang'an Tunnel

Xiamen Xiang'an Tunnel is located in the east of Xiamen Island, connecting Wutong of Huli District in the island and Xibin of Xiang'an District outside the island. The main line of the project is 8.695km long, of which the tunnel is 6.05km long. The three hole tunnel scheme with service tunnel is adopted. The left and right side are traffic tunnels (one-way traffic) and the middle is service tunnel (maintenance and escape passage). A total of six two-way lanes are set up, and the design driving speed is 80km / h Time. Xiang'an Tunnel is also the first subsea tunnel designed by Chinese experts.

Xiang'an Tunnel

Xiang'an Tunnel is a cross sea passage connecting Huli district and Xiang'an District in Xiamen City, Fujian Province, China. It is located at the estuary of Jiulong River and is an important part of the urban trunk road in the northeast of Xiamen city.

The construction of Xiang'an Tunnel started on April 30, 2005;

The tunnel connection project was completed on November 5, 2009;

It was put into operation on April 26, 2010.

Xiang'an Tunnel starts from Wutong interchange in the west, passes through Jiulong River Estuary in the bottom and Xiang'an interchange in the north; the total length of the line is 8.695 km, and the cross sea part is 6.05 km; the road is a two-way six lane urban trunk road with a design speed of 80 km / h; the total investment of the project is about 3.197 billion yuan.

Construction process

In 1996, Xiamen Municipal People's government put forward the idea of adding a new passage out of the island.

In 1998, Xiamen Municipal People's Government studied and designed the "East Passage" of Xiamen City, and put forward a feasible scheme.

In 2003, the national development and Reform Commission of the people's Republic of China approved that Xiamen needs a new passage out of the island.

In 2004, the State Environmental Protection Bureau of the people's Republic of China, the State Oceanic Administration of the people's Republic of China, the Ministry of communications of the people's Republic of China and other state ministries and commissions approved the project.

On April 26, 2005, the name of East Passage was determined as "Xiang'an Tunnel";

On April 30, the construction of Xiang'an Tunnel was started and a commencement ceremony was held;

On September 6, the construction personnel of Xiang'an Tunnel entered the construction site;

On September 15, Xiang'an end of Xiang'an Tunnel was constructed;

On October 1, the excavation of Wutong end of Xiang'an Tunnel was carried out;

On November 27, Xiang'an Tunnel started construction of service tunnel.

On December 5, the Xiang'an Tunnel was transferred to the Xiang'an end for construction.

On February 24, 2006, the Xiang'an Tunnel was transferred to the Wutong end for construction.

On June 20, 2007, Xiang'an Tunnel was excavated for the deep weathering trough.

On June 13, 2009, the right line of Xiang'an Tunnel was completed;

On November 5, 2009, the left line of Xiang'an Tunnel was completed and the whole tunnel was completed.

On April 15, 2010, Xiang'an Tunnel passed the completion acceptance;

On April 26, Xiang'an Tunnel was opened to traffic;

On April 28, Xiang'an Tunnel completed the full coverage project of communication signal.

Tunnel location

Xiang'an Tunnel is located in Xiamen City, Fujian Province, China, connecting Huli district and Xiang'an District. It starts from Wutong interchange composed of Xianyue road and Huandao trunk road in Huli District in the west, passes through Jiulong River Estuary in the north, reaches Xiang'an District in the north, and ends at Xiang'an interchange composed of Xiang'an Avenue and Xiang'an South Road along Xiang'an Avenue. The main route of the tunnel is Xiang'an Avenue.

Tunnel design

Tunnel structure

Overall layout

Xiang'an Tunnel is composed of surface road, underwater tunnel, service portal, two-way entrance and ramp. The main section of the tunnel is arranged from southwest to northeast.

 

Design features

The design of Xiang'an Tunnel adopts the three hole tunnel scheme, with three lane main driving tunnels on both sides, service tunnels in the middle hole and one ventilation shaft in the left and right tunnels. The plane layout of the tunnel adopts the combination curve to avoid or reduce the adverse effect of the weak structural zone on the tunnel. It is built in the form of three holes, with the main driving tunnel on both sides and the service tunnel in the middle; the tunnel section adopts a nearly circular three center circular arch.

 

Tunnel parameters

The total length of Xiang'an Tunnel is 8.695km, of which the length of the tunnel passing through the seabed is 6.05km, the width across the sea is about 4.2km, and the standard width is 64.14m. The design elevation of the lowest point of the tunnel is about - 70 meters, the distance between the road tunnel and the service tunnel is 22 meters, the distance between the left and right road tunnels is 50 meters, the section area of the inner contour of the tunnel building is 122 square meters, and the clearance section area above the carriageway is 100 square meters. The main tunnel has a clear width of 182.25 meters, a clear height of 5.0 meters, a clear space of 5 meters and 20 meters for the cross tunnel, a service tunnel inner contour of 39.325 square meters, a shaft diameter of 8.3 meters, an air supply area of 27.01 square meters and an air exhaust area of 24.92 square meters.

 

Equipment and facilities

On April 25, 2010, Xiang'an Tunnel was put into operation. The tunnel is equipped with ventilation system, water supply and drainage and fire fighting, power supply and lighting, monitoring system, communication system, toll system, signs, marking and management center.

 

Operation

Ticket price

On May 1, 2019, Xiamen Municipal People's government stopped collecting vehicle tolls for "four bridges and one tunnel" in Xiamen City, of which "one tunnel" is Xiang'an Tunnel.

 

Traffic matters

From March 15, 2019, Xiang'an Tunnel will implement the plan of lane change area to ensure the safety of lane change

Lane changing mode

In the direction out of the island, vehicles on the dotted line side are allowed to change lanes, while vehicles on the solid line side are not allowed to change lanes

1. The first group of lane changing areas allows vehicles to change lanes from 3 lanes to 2 lanes, and then from 2 lanes to 1 Lane;

2. In the second group, vehicles are allowed to change lanes from one lane to two lanes, and then from two lanes to three lanes;

3. The third group is the same as the first group;

4. Large and medium-sized passenger cars and trucks are not allowed to change lanes and can only drive in the right most lane.

In the direction of entering the island, vehicles on the dotted line side are allowed to change lanes, and vehicles on the solid line side are forbidden to change lanes

1. In the first group, vehicles are allowed to change lanes from one lane to two lanes, and then from two lanes to three lanes;

2. The second group of lane changing area allows vehicles to change lanes from 3 lanes to 2 lanes, and then from 2 lanes to 1 Lane;

3. The third group is the same as the first group;

4. Large and medium-sized passenger cars and trucks are not allowed to change lanes and can only drive in the right most lane.

Prohibited items

1. It is not allowed to change lanes frequently and arbitrarily. Lane changing is only allowed in the lane changing area without hindering the normal traffic of vehicles in the lane and adjacent lanes;

2. It is strictly forbidden for large and medium-sized passenger cars and trucks to change lanes in the tunnel. Xiang'an Tunnel is divided into three lanes, one-way three lanes, two lanes on the left are dedicated lanes for small passenger cars, and the rightmost lane is a mixed passenger and freight lane. Large and medium-sized passenger cars and trucks are only allowed to drive in the rightmost lane.

 

traffic flow

From January to April 2016, the two-way average daily traffic volume of Xiang'an Tunnel was nearly 100000 vehicles.

 

As of 2019, the average daily traffic volume of Xiang'an Tunnel island is about 91000 vehicles, and the average daily traffic volume of non working days is about 89000 vehicles.

 

Construction achievements

Technical problems

Construction problems

There are three major technical difficulties in the construction of Xiang'an Tunnel

1. The construction of large cross-section shallow buried excavation in fully weathered land area; 2. Construction of permeable sand layer in shoal section; 3. Construction of deep weathered trough on seabed.

 

construction technique

Aiming at the technical problems, the main technologies used in the construction of Xiang'an Tunnel are as follows:

1. The traditional CRD construction method was innovated and reformed. The continuous monthly excavation speed in soft surrounding rock was more than 60m, with the highest value of 73m, creating the world record of construction progress of super large cross-section subsea tunnel under the same geological conditions at that time.

2. The method of "well point dewatering of diaphragm wall" was used to successfully cross the water rich sand layer of more than 630 meters;

3. The "full section curtain grouting technology" and "grouting small pipe technology" are used to restrain the strong weathering trough.

 

Scientific research achievements

Honorary recognition

On April 21, 2010, the Ministry of transport of the people's Republic of China and the State Administration of work safety of the people's Republic of China issued a joint circular commending the work safety of Xiang'an Tunnel.

 

Cultural characteristics

"Never give up" relief

"Never give up" cave wall relief

Chinese PinYin : Xiang An Sui Dao