Project:

Machines:

Technology:

Rehabilitation of the Elevated Inner Ring Road in Shanghai, China

Tandem Roller HD O120V

Oscillation

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JOB REPORT #47

Night shifts on the skywayHD O120 V compacts the Elevated Inner Ring Road in Shanghai

HAMM HD O120 V on the elevated Inner Ring Road in Shanghai

Shanghai is the most populous city in the People’s Re-public of China and one of the largest urban areas in the world with a population of over 20 million people. Since the liberalisation of trade, the city of Shanghai and its economy have been growing rapidly. This growth is a tough challenge for the city architects in terms of in-frastructure. To save space, Shanghai decided to build elevated roads. Currently there are 6 elevated city roads and 18 expressways. Most of the elevated city roads are in downtown Shanghai.

HD O120V enables quick rehabilitation

One of these elevated roads, the 48 km long Inner Ring Road, was opened for traffic in 1994. Now, after 14 years in operation, some sections needed maintenance. The Shanghai Chengji Municipal Company was awarded for this contract. As this is a highly frequented road, the work mainly had to be carried out during night time. Each night a section of approx. 1.200 sqm was to be repaired. Therefore, the road was closed from midnight until 5 a.m. As a frist step, the old wearing course was milled out by a Wirtgen W 1900 large milling machine.

For the compaction of the new wearing course paved immediately after milling, Shanghai Chengji Municipal Company decided to use a HAMM HD O120V tandem roller because this machine fulfils all requirements includ-ing the economical and environmental friendly tasks. Moreover, with an operating weight of 12.250 kg and the HAMM oscillation technology it was the perfect machine for the compaction of the new SMA 13 wearing course on the elevated road.

Oscillation allows dynamic compaction even on bridges

HAMM oscillation is the only technology that can com-pact dynamically even on bridges or elevated roads. In Shanghai, after only three passes the tandem roller had compacted the SMA 13 to 99.16 %. This demonstrated impressively that oscillation rollers can achieve outstand-ing compaction results with only a few passes. This ad-vantageous technology is offered uniquely by HAMM. Other than vibratory rollers, HAMM oscillation rollers in-troduce tangential forces in the material to be compact-ed. During this process the horizontally moving drum rests in constant contact to the asphalt resp. soil layer. The dynamic oscillating movement in combination with the permanent static load of the drum guarantee a fast

JOB REPORT #47 Night shifts on the skyway

Dynamic compaction on an elevated road or bridge is possible with HAMM oscillation technology. This system allows even thin layers to be compacted without stressing the structures.

Shanghai – a growing metropolis

Originally a fishing town, Shanghai became China’s most important city in the beginning of the 20th century and was the centre of popular culture, intellectual discourse and political struggle during the Republican Period 1912 - 1948. After the Communist Revolution in 1949, Shanghai languished due to heavy central government taxation and cessation of foreign investment. Recent changes were in-troduced with the foundation of the New Open Economic Development Zone Pudong in 1990. Following the central government’s authorization of market-economic rede-velopment, Shanghai has now surpassed early-starters Shenzhen and Guangzhou, and has since led China’s economic growth.

Some challenges remain for Shanghai at the beginning of the 21st century, as the city struggles to cope with increased worker migration, a huge wealth gap and envi-ronmental degradation. Nevertheless, the Shanghai sky-scrapers and modern lifestyle represent China’s recent economic development. Widely regarded as the citadel of China’s modern economy, the city also serves as one of the nations’ most important cultural, commercial, fi-nancial, industrial and communication centres with one of the world’s busiest cargo ports.

increase of compaction paired with very homogeneous compaction and good surface roughness. Thereby the substructures are hardly affected. This is why dynamic oscillation can be applied even on bridges or other struc-tures sensitive to vibration. On the Shanghai skyway, a normal vibration roller would have had to work in static mode, without vibration. This would have needed more passes and thus more time without reaching the level of compaction achieved by the HD O120V. The saving of time and the outstanding compaction performance are two decisive application advantages offered by HAMM oscillation rollers.

HD O120V – two systems in one machine

Basically the machine is a „two in one”-roller as the front drum is equipped with vibration and the rear drum comes with HAMM oscillation. The roller is driven by a 4 cylinder Deutz diesel engine type TCD 2012 LO4 2V with a power rate of 100 kW at 2.300 rpm. A 185 l fuel tank ensures that the machine can operate at least one shift without refilling. The same fact counts for the 900 l water tank of the sprinkler system. The standard sprinkler system is pressurized and works with two pumps. An emergency system ensures sufficient water supply in any situation.

Night shifts on the skyway JOB REPORT #47

Happy faces after the results were released: The HAMM oscilla-tion roller achieved 99.8 % compaction degree. From left to right: Hu Liping – Section Chief of Equipment Department at Shanghai Chengji Municipal Company, Jerry Xu – Sales Manager of Wirtgen Shanghai, Hans Wang – Service Engineer of Wirtgen Shanghai

After only a few passes in oscillation mode the required compaction was achieved. This feature is a real advantage of application when the time slot for compaction is short like on this job site.

Cleaning the noise fences was included in the contract, too. These fences are important, as the Inner Ring Road leads through busi-ness and housing districts of Shanghai.

24 h service and support

However, the machine itself is not the only key to suc-cess. Mr. Hu Liping, Section Chief of Equipment Depart-ment at Shanghai Chengji Municipal Company, explains why: „It is not only the machine but also the outstanding after sales service, repair, training and application support offered by WIRTGEN CHINA that eases the operation. With the assembling, repair and service centre in Lang-fang (Hebei) and additional service centres in Shanghai, Guangzhou and Xi`an, support is always close to us. So WIRTGEN CHINA supports jobs like this in Shanghai with a 24 h service on site, for example. Even if usu-ally the services of the HAMM engineers remain unused, their presence gives us the safety we need on night jobs like this where there is a strict deadline to finish work at 5 a.m. every morning. Nobody would like to imagine what happened if the Inner Ring Road could not be opened in the morning. Everyone who has been in Shanghai, knows what it means ...”

The front vibration drum can reach a centrifugal force of 186 kN, the rear oscillation drum can even reach up to 279 kN. In crab steering mode, the roller with a drum width of 1.980 mm can extend its working width up to 2.090 mm. Besides the technical features also the op-erator is in focus of the HAMM design team. A swivelling and turning operator’s seat with two multifunction levers on the left and right hand side allows the operator a clear view on the edge of the drum.

All these features are important for a successful opera-tion and of course for an excellent result. Furthermore, the fact that HAMM combined two dynamic systems in one roller pays off financially. Using the oscillation sys-tem, the roller components are exposed to considerably less stress and thus achieve an extended service life.

JOB REPORT #47 Night shifts on the skyway

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1.09

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The Inner Ring Road empty and quiet – this is something very unu-sual! Normally, this road is heavily trafficked night and day.

F 12250 kg

G 1980 mm

E 100 kW

HD O120V

HAMM AG

Hammstraße 1

D-95643 Tirschenreuth

Tel +49 9631/ 80-0

Fax +49 9631/ 80-120

www.hamm.eu