Projects
Nehemiah Anchored Earth (AE) wall was first introduced in Malaysia in 1993. Since then, it has gained wide acceptance not only in Malaysia but overseas as well. The technology has been exported to Singapore, Sri Lanka, Bangladesh, India and now to Australia, New Zealand and the Pacific Islands. To date over 700,000 m2 of walls has been built with varying heights, configurations and applications. The highest wall that has been built so far is 20.5m high. The reasons for the popularity of the Nehemiah AE wall are cost effectiveness, versatility, excellent performance, attractive appearance and speed of construction. The Nehemiah AE wall is applicable in a wide range of situations.
These applications include :
Urban Highway Interchanges
Of all the various applications, this category of application is the most popular. This is because the Nehemiah wall is ideal for situations where fill is needed to construct interchanges, which is true for many new highway construction project interchanges. Construction is rapid and the interference with existing vehicular traffic is minimised due to the "erection from behind" construction methodology implemented. The large number of Nehemiah walls used for the Kuala Lumpur Middle Ring Road II project is a testimony of their popularity. The SPRINT expressway project in Kuala Lumpur (Photo 1) and the Autopont Bridge project along Jalan Masjid Negeri in Penang (Photo 2) clearly illustrate the application for urban highway interchanges.
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Photo 1 : Sprint Expressway, Kuala Lumpur |
Photo 2 : Autopont Bridge along Jalan Masjid Negeri, Penang |
River Wall
The design of Nehemiah walls for river application is a different situation altogether. The design has to cater for the hydraulic head differential during rapid draw down conditions. In addition, the toe of the wall needs to be protected from the effects of scouring. The bouyancy and seepage forces also have to be factored in during the design computation. Photo 3 illustrates the use of Nehemiah wall for the widening and deepening of the Klang River.
The wall is designed to withstand floods whereby the wall is submerged.
Photo 3 : Sg. Klang River Wall, Kuala Lumpur
Slope Repair
Unlike river wall or highway applications ,the frequency of this type of application is relatively low. However they are often critical and urgent. The approach to solve slope failure problems is to use Nehemiah wall as a gravity buttress at the toe to provide stability.
Click here for an image of a typical cross-section.
Railway Embankments
The requirements for railway applications are similar to those for highways except that the settlement criteria for railways is often more stringent. In addition, dynamic forces due to vibration from the rail have to be considered.
Click here for an image of a typical cross-section of a railway embankment.
An integral part of railway and highway approach embankments is the bridge abutment. Nehemiah wall also finds application in this situation.
Bridge Abutment
In this application, the bridge loads are often transferred to the bankseat which is in turn supported by piles or external columns as shown in Photo 4. Under this circumstance, the Nehemiah wall is acting merely as a retaining wall. However, if the subsoil is sufficiently strong, the Nehemiah wall can be designed to be load bearing and carry the bridge load directly.
Photo 4 : Bridge Abutment at Nilai Perdana, Negri Sembilan
Housing Development
Nehemiah wall has often been used for housing developments to maximise useable land especially in urban areas where the land cost is high. In rural areas where the land cost is low, it is more common and often cheaper to use earth slopes instead of retaining walls.
Photo 5 : Kurnia Perdana Condominium at Kota Kinabalu, Sabah
Industrial Development
Besides housing, industrial developmentc can also benefit from use of Nehemiah wall. Photo 6 shows an application for a LNG tank farm and Photo 7 shows an application for a factory in Senawang.
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Photo 6 : Kulim Hi-Tech Park, Kedah |
Photo 7 : Goodmaid Chemical Factory at Senawang, Negeri Sembilan |
Case Histories
