2008-213 (5) - Laserfiche WebLink

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This procedure may be used so long as, in the opinion of the Engineer, the work is proceeding satisfactorily. The Engineer may revoke permission to use the "trench box" at any time he feels unsatisfactory or inadequate work is being performed and the Contractor shall, without appeal, immediately begin using sheeting, bracing and shoring to maintain the allowable trench widths. At all times, when soil conditions permit, the bottom edge of the "trench box" shall be no lower than the springline of the pipe, so as to disturb the trench compaction when advancing the "trench box". 5) Placing of Excavated Material - All excavated materials shall be placed where indicated by the Engineer in such a manner as not to endanger the work and so that free access will be maintained at all times to all parts of the trench and to all fire hydrants and their gate valves in the vicinity. Such material shall be neatly piled so as to interfere as little as possible with traffic. 6) Drainage - The Contractor shall furnish sufficient pumping or other dewatering equipment and shall provide at his own expense satisfactory drainage whenever needed in trenches and other excavations during the progress of the work and its completion for inspection. Water shall not be allowed to flow over or raise upon any concrete, masonry or pipe until work has been inspected and the mortar or concrete has properly set. Unless otherwise permitted by the Engineer, the water table shall be lowered by the use of a well point system. Open trench pumping may be permitted only upon approval by the Engineer of the method of pumping and drainage to be used. If open trench pumping is approved, the water must be conveyed entirely through approved coarse material placed below the bottom of the foundation. The depth of this coarse material shall be determined by the Contractor and approved by the Engineer. Materials and workmanship used for the well point system shall be in keeping with the approved standard practice. The well point system shall function so as to enable pipe, concrete cradle and appurtenances to be installed without interference from running or standing water at the bottom of the trench. The Engineer shall make the final decision as to the acceptability of the well point system or any part thereof. Where necessary, pea gravel or graded sand shall be used in conjunction with the well points as they are installed in insure continuous pumping in the dewatering of fine material. The cost of dewatering shall be included in the various unit prices bid under the mainlines. 7) Disposal of Water from Excavations - All water pumped or bailed from trenches or other excavations shall be conveyed in a proper manner to a suitable point of discharge by the Contractor at his own expense. The Contractor shall provide for the disposal of water removed from excavations in a manner that will not cause injury to public health, private or public property, any portion of the work completed or in progress, the surface of the streets, or cause any impediments to the reasonable use of the site by other Contractors. The Contractor shall be responsible for complying with all the local regulations and those of the 02534- Sanitary Sewer Force Mains 02534 - 6