Improvement of iron ore stockyard berms using cementitious stabilisation

Australia is one of the largest iron ore producing countries in the world. As a result of recent increased demand for iron ore in the international market, development of new open pit mines with associated construction of new iron ore stockyard facilities and expansion of existing facilities have been on the rise in Western Australia. Design of stacker and reclaimer machine berms with the intent of optimising stocking capacity have been the key issue for construction of these iron ore handling facilities. Improvement of embankment materials is often required to ensure adequate safety against bearing capacity and global slope failure, and limit embankment deformation under reclaimer and stacker machine loadings. This paper presents ground improvement undertaken at stockyard berms of a large iron ore handling facility located in the Pilbara Region of Western Australia. The machine berms were designed to support large vertical and horizontal loadings. Locally available materials were used to construct the machine berms. Finite element analysis using PLAXIS computer program was undertaken to assess strength and stiffness requirements of the berm materials. Cement stabilisation was adopted for improvement of berm materials based on results of rigorous laboratory testing. In situ cement stabilisation of the berm materials was carried out using a Bomag stabiliser machine. Plate load tests were undertaken to assess degree of ground improvement using cementitious stabilization, and assess modulus of the stabilsed materials. Results of laboratory testing, in situ stabilisation, assessment of stabilised materials using plate load tests and finite element analysis methods are discussed in this paper.