to hydraulic breakers and the WS-Series is one of the quietest in the industry, making it excellent for use in areas with noise restrictions. Drum cutters also produce less vibration than breakers, so contractors can use them where there’s a risk of disturbing a nearby structure’s foundation. The low decibel output and minimal vibrations of the attachments are achieved through a high-torque hydraulic motor, which powers the drum cutter while its gear reduction optimizes torque and cutting force. The rock drum effectively breaks soft to medium-hard rock in mines and quarries with its strategic chisel pattern while the profiling drum’s higher density of chisels shapes and levels soft to medium-hard rock in tunneling applications. The demolition drum offers reduced vibrations due to a wear-protected spiral sheet and is ideal for cutting medium- hard to hard rock as well as concrete. Nicolas Denies, deputy head of laboratory, and Noël Huybrechts, head of the geotech- nical division at BBRI, Belgium, have pub- lished “Handbook – soil mix walls: Design Hub Foundation Enters Slurry Wall Market Hub Foundation has entered the slurry wall market with a new Bauer slurry handling system in Boston, Mass., which also marked the first time Equipment Corporation of America (ECA) has sold this machinery in North America. A Bauer MC 96 duty-cycle crane with a BC 35 trench cutter and a Bauer MAT DE 500-20 slurry handling system was used to install foundations for a 45-story residential tower at Bulfinch Crossing. Hub has a well-established reputation as a high-quality drilled shaft contractor, and, although Hub had developed expertise in bentonite slurry over the years, its leadership team had debated whether or not to enter the slurry wall market. Bulfinch Crossing, a project Hub had under agreement, made the decision clear. The geotechnical engineers had changed course on the Bulfinch Crossing project, and what started as a drilled shaft and micropile project would then include a slurry wall with Load Bearing Elements (LBE). Prior to the start of the work, Hub visited projects in France, Germany and Israel to see the equipment in action and learn from contractors using the machinery. Mobilizing the equipment and keeping it running properly was critical, especially when the owner delayed the project. Hub hired an industry expert to keep the project running smoothly, and ECA hired a BAUER Maschinen technician to be on standby for the duration of the job so he could get to the and execution,” through CRC Press. It is the first ref- erence handbook dedi- cated to the use of soil mix as structural elements for the construction of earth- water retaining structures and cut-off walls. The handbook establishes the link between the functional requirements, the design and the quality control of the final soil mix struc- ture. The design methodology presented in this handbook is in agreement with the Eurocodes. Order at www.crcpress.com. project quickly without having to fly from Germany. The technician set up the slurry handling system, mobilized the crane and cutter, and trained Hub’s personnel. Hub was onsite from December 2017 through May 2018, although the slurry wall work took place from February through April. A Bauer MC 96 with a BC 35, a 41.3 ft (12.6 m) high by 9.2 ft (2.8 m) long unit with four cutter wheels, was used to exca- vate the 36 in (914 mm) thick slurry wall. LBEs were installed to a depth of about 75 ft (23 m) to support the load of the tower. The MAT DE 500 slurry handling system consisted of two desilters and an agitation tank, which together were used to remove soil particles from the bentonite slurry during excavation of the slurry wall and LBEs. The excavation was more shallow than anticipated. At the project site, the Boston Blue Clay was underlain by Glacial Till and Cambridge Argillite. Hub used a separate crane with a hydraulic grab to start the panel excavation, and then used the BC 35 to clean and finish the rock sockets, which ranged in length from 17 to 33 ft (5.2 to 10 m). There were 22, 36 in (914 mm) thick panels ranging from 9.2 to 22.7 ft (2.8 to 6.9 m) long by 70 to 84 ft (21.3 to 25.6 m) deep, 8 of which interlocked to form the core wall. In addition, there were 107 micropiles ranging from 85 to 130 ft (26 to 39.6 m) deep, 3 drilled shafts with a diameter of 4 ft (1.2 m) and a depth of 85 ft (26 m), and 42 additional piles for the support of excavation. 130 • DEEP FOUNDATIONS • NOV/DEC 2018
