404 PROTECTION OF EXISTING STRUCTURES

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404.01 DESCRIPTION
Protect existing structures due to open excavation, pile placement, sheet pile installation, blasting, removal of existing bridge, or any other item that may affect the existing structures, at locations specified in the Contract Documents.
404.02 MATERIALS
Not applicable.
404.03 CONSTRUCTION
404.03.01 Preconstruction Survey. Retain an approved, experienced seismologist for monitoring and registering vibrations in adjacent and nearby structures as specified. This protection shall be for any structure that may be liable to any damaging effects of any construction activity operations.
Retain an approved commercial photographer.
Retain an approved professional engineer registered in Maryland who is experienced in the field of building inspection surveys. This professional engineer will be referred to hereinafter as "Building Inspector.”
Prior to beginning any work, the Contractor, the insurer, photographer, building inspector, seismologist, and the Engineer, shall make a detailed inspection of each structure to record the condition of all walls, and other structural elements, as well as its contents and equipment that may be in place, and pavements and sidewalks that may become subject to possible damage claims.
Before any inspections are performed, notify the owners of the structures involved, which have been approved by the Engineer, requesting their permission to enter upon the properties for the purpose of making these inspections for the protection of the owner.
In the event that access for the purpose of determining the condition of the buildings and structures is refused by any owner, the Contractor shall notify the Engineer in writing and may there upon be relieved of the responsibility for making the survey with respect to the property to which access is denied.
Where possible, have the owner or a representative of the owner present during these inspections and secure the signature of the owner/representative on the completed documents, submitting a copy to the owner/representative.
Provide a record of the pre-construction survey. The record shall consist of a written report including measurements, sketches, and photographs as required to fully delineate the extent of or lack of deficiencies.
Photographs shall be 8 in. x 10 in. size, in color, and include views inside and outside of the existing structures.
A notarized statement certifying the date that each preconstruction survey was made shall be furnished by the Contractor, the building inspector, the seismologist, and the photographer to the Engineer. This certification shall include a statement that the preconstruction survey was made in the presence of and to the satisfaction of the respective owners.
Furnish the written report and photographs to the Engineer at least two weeks prior to beginning any vibration producing work. The written report shall state acceptable levels of vibrations at the various existing structures together with the Contractor’s procedures proposed for use for the various construction activities so as not to exceed the acceptable levels of vibrations. The seismologist shall submit to the Engineer the proposed methods for monitoring construction activities effects on adjacent structures, including work plans that indicate the type and layout of sensing devices. The proposed methods and plans shall be approved by the Engineer prior to any construction activity.
Forward a copy of all data relative to existing conditions of each respective property as found by the preconstruction survey to each property owner. Submit two identical copies to the Engineer.
404.03.02 Construction Vibration Surveillance. During construction the seismologist shall record vibrations, during structure pile installation and any sheet piling operations, blasting, removal of existing structure, or any other activity that may cause excessive vibrations near any adjacent structure.
The seismologist shall record the vibrations and direct the construction activities operations in order to eliminate the occurrence of damage due to the construction activities.
If any construction activity has an adverse effect on adjacent structures as determined by the seismologist or the Engineer, the construction activity operations may be suspended while corrective action is being taken. The surveillance shall continue as long as required by the Engineer.
Do not exceed the acceptable vibration levels contained in the preconstruction written report.
404.03.03 Post-construction Inspection. Upon completion of the work, and prior to final acceptance of the project, the Contractor with their insurer, building inspector, and with the Engineer and property owner, shall re-examine each property to determine any changes from the original conditions established by the preconstruction survey.
404.04 MEASUREMENT AND PAYMENT
The protection of existing structures including all costs of the preconstruction and post-construction surveys, seismologist, building inspector, photographer, preparation and submission of written reports, and all material, labor, equipment, tools and incidentals necessary to complete the work will be measured and paid for as specified in the Contract Documents. The work under this item will be excluded from the 50 percent subletting clause as specified in GP-8.01.
When specified in the Contract Documents, the protection of existing structures will not be measured but will be paid for at the Contract lump sum price for the Protection of Existing Structures item.