Trench Excavation. Trenches for all pipe lines and culverts shall be excavated to required lines and bottoms taken out to the exact gradients using profiles and boning rods or other suitable devices. The trench shall be of sufficient width to enable the pipes to be properly laid and jointed. No excavation shall be filled in or covered with concrete until the Engineer has inspected it and the Contractor has been authorised to proceed with the works. All surplus excavated materials from such excavation not required for refilling shall be carted away to tips or otherwise disposed of, as directed. All excavations shall be kept dry and all bating and pumping timbering shoring and supporting of sides that may be required, and any refilling, ramming and disposal of surplus materials necessary in carrying out the excavations and back filling of trenches shall be included in the prices of excavations. Special care shall be taken to provide a solid bed for the barrels of the pipes and where a concrete bed is not specified, the floor of the trench shall be properly shaped to receive the socket. The length of the trench open ahead of pipe laying shall not exceed 200 m. Trenches shall have a width not less than that shown on the drawings and shall have vertical sides unless the Engineer has approved the use of sloping sides in lieu of timbering. The bottom 50 mm of trench shall be left undisturbed until immediately before the pipe is to be laid when it shall be trimmed accurately by hand to the correct grade. If no bedding is required joint holes shall be formed as necessary so that the pipe, when laid is bedded on the entire length of its barrel on the firm and undisturbed bottom of the trench.
Trench Excavation. 13.7.1 Trenches Greater Than Five Feet Pursuant to Labor Code section 6705, if the Contract Price exceeds $25,000 and involves the excavation of any trench or trenches five (5) feet or more in depth, the Contractor shall, in advance of excavation, submit to the Owner or a registered civil or structural engineer employed by the Owner a detailed plan showing the design of shoring for protection from the hazard of caving ground during the excavation of such trench or trenches.
Trench Excavation. This Section shall apply to the Contract only if the Contract Amount exceeds twenty-five thousand dollars and the Work requires or involves excavation of any trench or trenches five feet or more in depth. The Contractor, in conformance with Labor Code Section 6705 and other applicable law, and prior to any such excavation, shall submit to the District for review and approval a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from the hazard of caving ground during the excavation of such trench or trenches. The plan must be prepared by a registered civil or structural engineer and if the plan varies from the requirements of applicable Cal-Osha Construction Safety Orders, the Contractor must obtain Cal-Osha approval of the plan. Nothing in this Section, and no District or other approval of any plan prepared pursuant to this Section, shall relieve the Contractor of any responsibility, or result in District liability for hazards resulting from excavations performed by the Contractor.
Trench Excavation. Before commencement of trenching provide inlet protection for all downhill storm drain catch basins per City of Black Diamond and Washington Department of Ecology standards. Plastic sheeting must be available on-site. Any stockpiled material must be covered and secured if raining or left unattended overnight. Clearing and grubbing limits may be established by the Engineer for certain areas and the Contractor shall confine his operations within those limits. Debris resulting from the clearing and grubbing shall be disposed of by the Contractor. Trenches shall be excavated to the line and grade designated by the Engineer and in accordance with the Standards. Trenches shall comply with OSHA and WISHA requirements regarding worker safety. Where higher strength pipe or special bedding is required because of excess trench width or depth, it shall be furnished. The trench shall be kept free from water until joining has been completed. Surface water shall be diverted so as not to enter the trench. The Contractor shall maintain sufficient dewatering equipment on the job to ensure that these provisions are carried out. The Contractor shall perform all excavation of every description and of whatever substance encountered as part of his trench excavation cost. Unsuitable material below the depth of the bedding shall be removed and replaced with satisfactory materials as determined by these Standards, the Standard Specifications, and the Engineer. Trenching operations shall not proceed more than 100’ in advance of pipe laying except with written approval of the Engineer. When trenching operations take place in the public right-of-way, the pavement, and all other improvements, shall be restored as required by these Standards.
Trench Excavation. Dredging techniques including grab dredging, cutter suction and trailer suction dredging are considered and chosen depending on the engineering, environmental and risks conditions. As the submarine watermain will be located across the Yau Ma Tei, Central and Southern Fairway, grab dredging is selected, as cutter suction and trailer suction dredging which requires a working area of over 150m in width, will result in an unacceptable impact on marine traffic and thus are not feasible. Suction dredging will also produce more marine sediment by volume when compared with grab dredging. Grab dredging is therefore the best practicable and feasible method to minimize dredging and dumping requirements and demand for fill sources. In the bottom pull method, pipes are joined to form pipe strings which are progressively pulled from a landfall site into a pre-dredged trench underwater by a winch set up at the landfall site at the other side of the waters until the crossing is complete. This method is one of the most common method for installation of medium to large diameter pipelines. In the lay barge method, while the work barge moves along the pipeline, the pipes are progressively added to form a string, which are hung in a catenary from at the back of the barge, and are gradually lowered into the pre-dredged trench. As the lay barge method will introduce intolerable marine traffic impact due to its long suspended pipeline at sea during the installation, this method is considered not a feasible option. In the float and sink method, lengths of pipe are made up into strings at a fabrication yard and these strings are launched to seabed from one of the landfall sites. These prefabricated pipe strings are temporarily stored on the seabed before towed by work barge at or below the water surface to the pre-dredged trench. By removing or filling water to the supporting buoyancy tanks, the pipe strings are sunk to its final position. This method is also one of the most common method for installation of medium to large diameter pipelines.
Trench Excavation. A. Topsoil and grass shall be stripped a minimum of 6-inches over the trench excavation site and stockpiled separately for replacement over finished graded areas.
Trench Excavation. This Article shall pertain to all Construction comprising the excavation of any trench or trenches four (4) feet or more in depth. Design-Builder shall submit to the Owner, in advance of excavation, a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from the hazard of caving ground during the excavation of any trench or trenches four (4) feet or more in depth. Design-Builder’s plan shall be prepared by a registered civil or structural engineer. As a part of the plan, a note shall be included stating that Design-Builder’s registered civil or structural engineer certifies that the plan complies with the current and applicable CAL-OSHA Construction Safety Orders, or stating that Design-Builder’s registered civil or structural engineer certifies that the plan is not less effective than the shoring, bracing, sloping, or other provisions of the Safety Orders. All shoring submittals shall include surcharge loads from adjacent embankments, construction loads, and spoil bank. Submittals shall indicate minimum horizontal distance from top of trench to edge of all surcharge loads for all cases of shoring and side slopes. Nothing in this Article shall relieve Design-Builder of the full responsibility for providing shoring, bracing, sloping, or other provisions adequate for worker protection. Pursuant to Labor Code § 6705, nothing in this Article shall impose tort liability upon Owner, its Board, the Executive Director or any of its employees. In relation to digging trenches or other excavations that extend deeper than four (4) feet below the surface of the ground, Design-Builder shall comply with the following requirements, and include similar provisions in any contract for the Project, which involves digging trenches or other excavations: That the Design-Builder shall promptly, and before the following conditions are disturbed, notify the Owner, in writing, of any: Material that the Design-Builder believes may be material that is hazardous waste, as defined in § 25117 of the Health and Safety Code that is required to be removed to a Class I, Class II, or Class III disposal site in accordance with provisions of existing law. Subsurface or latent physical conditions at the Site differing from those indicated. Unknown physical conditions at the Site of any unusual nature, different materially from those ordinarily encountered and generally recognized as inherent in work of the character provided for in t...
Trench Excavation. According to the engineering plans, a 36” PVC pipe having an outer diameter of approximately 42 inches will be placed in a trench to be excavated beneath the of the existing canal T-131. The trench will be excavated to a depth of 7.5 feet to accommodate a sand bedding layer while allowing for more than 3 feet of cover over the top of the pipes. It is estimated that a 4.5-foot bottom width will be required to the full 7.5-foot depth, while an 9.5-foot-wide security bench will be needed to a depth of 3 feet, resulting in a trench cross-section of 48.75 square feet. This trench requires 3,250 B.C.Y. of excavation. Excavation will be carried out with a 1-cubic- yard backhoe similar to a Caterpillar 420E.
Trench Excavation. Pursuant to Labor Code Section 6705, if this Agreement is for more than $25,000 and requires the excavation of any trench or trenches five feet or more in depth, Contractor shall submit, in advance of such excavation, a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from the hazard of caving ground during the excavation of such trench or trenches. The plan shall be reviewed and accepted by the City, or a registered civil or structural engineer employed by the City to whom authority has been delegated, prior to the excavation. If the plan varies from the shoring system standards, the plan shall be prepared by a registered civil or structural engineer. This Section 1.8 shall not be deemed to allow the use of a shoring, sloping, or protective system less effective than that required by the Construction Safety Orders (set forth in the California Code of Regulations, Title 8, Subchapter 4). This Section 1.8 shall not be construed to impose tort liability on the City or any of its employees. Full compensation for sheeting, shoring, bracing, sloping, and all other provisions required for worker protection shall be considered as included in the contract price shown in the appropriate Bid item in the Contract Documents, and no additional compensation will be allowed therefor.
Trench Excavation. Pursuant to Labor Code section 6705, if this Agreement is for more than $25,000 and requires the excavation of any trench or trenches five feet or more in depth, Contractor shall submit, in advance of such excavation, a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from the hazard of caving ground during the excavation of such trench or trenches. The plan shall be reviewed and accepted by the City, or a registered civil or structural engineer employed by the City to whom authority has been delegated, prior to the excavation. If the plan varies from the shoring system standards, the plan shall be prepared by a registered civil or structural engineer. This section shall not be deemed to allow the use of a shoring, sloping, or protective system less effective than that required by the Construction Safety Orders. This subsection shall not be construed to impose tort liability on the City or any of its employees. Full compensation for sheeting, shoring, bracing, sloping, and all other provisions required for worker protection shall be considered as included in the contract price shown in the appropriate Bid Item, and no additional compensation will be allowed therefor.
