The Arab Potash Company’s (APC) site is located at the southern end of the Dead Sea in Jordan. Dike 1 is approx. 11.5 km long, forming the perimeter for several salt pans. The potash salt, being the basis for Carnallite production is obtained in several solar ponds with an area of 112 km², where the coveted raw material is concentrated by evaporation. What is interesting about this is that the basins are located around 400 m below mean sea level and therefore at the lowest point on earth (above water). The main purpose of this project is to rehabilitate the existing dikes to improve their stability, mitigating the development of sink holes/cavities and interception of leakages from the ponds with associated losses of carnallite.

Geology:

Fill, hard crystalline salt layers, clay

Scope of works:

Approx. 311,000 m² cut-off wall over a length of 11.2 km with a width of 640 mm. The actual wall set-up was varied between various sections. One stretch of the wall was excavated down to 18 m in combination with sheet piles driven by vibro equipment some 4 meters into the soil below the bottom of excavated panels. Other stretches of the cut-off wall were constructed down to maximum 30 m with installation of suspended sheet piles.

Miscellaneous:

Harsh weather conditions, temperatures approaching 50 °C, and an extremely salty environment were just part of the challenges.

The subsoil presented a special challenge: The hard crystalline salt layers required the use of two Bauer cutter units in combination with one grab unit. Also, the tremendously critical effect of the high salt content on the support fluid had to be addressed by developing innovative custom-made compositions. The detailed production tracking with Bauer’s b-project software provided, besides the web-based visualization of the progress, an effective instrument for the management and control of high-quality level of the construction works. The completed sections of the wall, extending over several kilometres, have proven total efficiency. Measurements of the unambiguously significant raise of the differential hydraulic head on both sides of the cut-off wall, besides the completely disappeared water flow stretches on the downstream side, provided clear evidence for the success of the executed works to the stakeholders.

INFO

Construction Method:             Diaphragm wall, earthworks

Construction Materials:           Plastic concrete, sheet piles

Main Equipment:                   BAUER Cutter and grab

Construction Period:              January 2019 - December 2021 (ongoing)