COFFERDAMS Clause Samples
The COFFERDAMS clause defines the requirements and responsibilities related to the construction, maintenance, and removal of cofferdams on a project site. It typically specifies that the contractor must design and build temporary watertight enclosures to allow work below the waterline, such as bridge foundations or underwater repairs, and ensure their stability and safety throughout the project. This clause ensures that underwater or below-water construction can proceed safely and efficiently by clearly assigning responsibility for these temporary structures and mitigating risks associated with water intrusion.
COFFERDAMS. Whenever water is present in the upstream watercourse, a temporary cofferdam shall be installed upstream of the damaged tidegate/floodgate prior to initiating any excavation activity below OHW line in order to isolate the project site from the upstream watercourse.
COFFERDAMS. Suitable and practically watertight cofferdams shall be used wherever water-bearing strata are encountered above the elevation of the bottom of the excavation. If requested, the Contractor shall submit drawings showing his proposed method of cofferdam construction, as directed by the Engineer. Cofferdams or cribs for foundation construction shall in general, be carried well below the bottoms of the footings and shall be well braced and as nearly watertight as practicable. In general, the interior dimensions of cofferdams shall be such as to give sufficient clearance for the construction of forms and the inspection of their exteriors, and to permit pumping outside of the forms. Cofferdams or cribs which are tilted or moved laterally during the process of sinking shall be righted or enlarged so as to provide the necessary clearance. When conditions are encountered which, as determined by the Engineer, render it impracticable to ▇▇▇▇▇▇▇ the foundation before placing the footing, the Engineer may require the construction of a concrete foundation seal of such dimensions as he may consider necessary, and of such thickness as to resist any possible uplift. The concrete for such seal shall be placed as shown on the Plans or directed by the Engineer. The foundation shall then be dewatered and the footing placed. When weighted cribs are employed and the mass is utilized to overcome partially the hydrostatic pressure acting against the bottom of the foundation seal, special anchorage such as dowels or keys shall be provided to transfer the entire mass of the crib to the foundation seal. When a foundation seal is placed under water, the cofferdams shall be vented or ported at low water level as directed. Cofferdams shall be constructed so as to protect green concrete against damage from sudden rising of the stream and to prevent damage to the foundation by erosion. No timber or bracing shall be left in cofferdams or cribs in such a way as to extend into substructure masonry, without written permission from the Engineer. Any pumping that may be permitted from the interior of any foundation enclosure shall be done in such a manner as to preclude the possibility of any portion of the concrete material being carried away. Any pumping required during the placing of concrete, or for a period of at least 24 hours thereafter, shall be done from a suitable sump located outside the concrete forms. Pumping to ▇▇▇▇▇▇▇ a sealed cofferdam shall not commence until the seal has set s...