Common use of Retaining Walls Clause in Contracts

Retaining Walls. The original scope of services did not include design and detailing of retaining walls within the project. Although the structural design will be provided by other consultants, TerraVista NW will need to prepare wall profiles to support the structural design of the walls. Also, additional time was spent in determining the extents of the retaining walls and viable locations within the project site and private property. ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇, ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇ The original scope of services was based on what was known at the time the contract was drafted and what would be anticipated for the project. As the design progressed through 30% and 90% development, the complexities of a project that had significant topographic differences resulted in additional time being spent to develop grading of the roadway approaches, beyond what was originally assumed. Roadway approach grading needed to be significantly adjusted several times to try to minimize impacts to driver experience, adjacent driveways, overall earthwork, existing utilities, and so on. This added effort would benefit the overall project budget and coordination with property owners. Task 1 – Project Management and Coordination TerraVista NW will perform the following additional tasks: • Contract management • Coordinate with the design team on aspects related to flow control and water quality systems • Coordinate with Agency on allowable treatment systems and code interpretations. • Participate in additional periodic online coordination meetings. • Perform QA/QC review Task 2 – Data Gathering and Engineering TerraVista NW will perform the following tasks: • Review studies and documentation provided by others • Perform up to one (1) additional site visits Task 3 – Preliminary Design TerraVista NW will perform the following tasks: • Review options for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 30% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Task 4 and 5 - Final Design TerraVista NW will perform the following tasks: • Review options for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 90% and 100% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Assumptions

Retaining Walls. A. The original scope of services did not include Engineer shall develop each retaining wall design and detailing determine the location of each soil boring needed for the foundation design of each retaining wall in accordance with the Geotechnical Manual. B. Prior to preparation of retaining wall layouts, the Engineer shall prepare a comparative cost analysis of different types of retaining walls versus roadway embankment, pavement, soil stabilization, retaining walls type, and available ROW to determine optimum selection based on economics, construction time duration, ROW encroachments (need for construction easements) and construction feasibility. C. The Engineer shall submit early in the plan preparation the retaining wall layouts to obtain approval from the State. The Engineer shall incorporate all necessary information from above referenced manuals and respective checklists into the retaining wall layouts. D. For stage construction, the Engineer shall indicate limits of existing retaining walls for removal and reconstruction, and determine limits of temporary retaining walls to be shown on the TCP. E. For projects designed using Bentley’s OpenRoads 3D modelling Technology, the retaining walls must be represented in the 3D model. F. The approximate limits of each retaining wall shall be based on Station or length. The Engineer shall notify the State the type of retaining walls that will be used for Cut and Fill locations. Retaining wall types may include:  Spread Footing Walls (High Footing Pressure Design and Low Footing Pressure Design). The Engineer shall select a spread footing wall for fill situation when considerable room behind the walls is available for forming, constructing, and backfilling the footings and stem. The Engineer shall notify the State when the quantity is less than 1000 square feet to have as option in the plans to cast in place a spread footing wall design. This selection has to be approved to State. DocuSign Envelope ID: 6DA01770-719C-4EFF-A344-425189FAC6FB  Mechanically Stabilized Earth (MSE) Walls. The Engineer shall prepare the retaining wall layouts showing plan and profile or retaining walls for design by a State approved vendor. The Engineer is responsible for design of geometry and wall stability. The Engineer shall incorporate a slope of 4:1 or flatter from the existing and finished ground line elevation to the face of the retaining wall.  Concrete Block Walls (Structural and Landscape).  Tied Back Walls.  Soil Nailed Walls.  Rock Nailed Walls.  Drilled Shaft Walls.  Temporary MSE Walls. G. The Engineer shall select any necessary standard details from State or District’s list of standards for retaining wall items. H. The Engineer shall provide special retaining wall details which are not currently provided by the State or District’s list of standards. I. The Engineer shall provide layouts (scale 1”=100’), elevations, quantity estimate, summary of quantities, typical cross sections and structural details of all retaining walls within the project. Although The Engineer shall determine if any additional retaining walls are required and verify the structural design will be provided by other consultants, TerraVista NW will need to prepare wall profiles to support the structural design of the walls. Also, additional time was spent in determining the extents for and length of the retaining walls and viable locations within as shown on the project site and private propertyschematic. ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇, ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇ The original scope of services was based on what was known at the time the contract was drafted and what would be anticipated for the project. As the design progressed through 30% and 90% developmentIf applicable, the complexities of a project that had significant topographic differences resulted in additional time being spent to develop grading of the roadway approaches, beyond what was originally assumedState will provide architectural standard drawings. Roadway approach grading needed to be significantly adjusted several times to try to minimize impacts to driver experience, adjacent driveways, overall earthwork, existing utilities, and so onThe Engineer shall incorporate architectural standard drawings into design details. This added effort would benefit the overall project budget and coordination with property owners. Task 1 – Project Management and Coordination TerraVista NW will perform the following additional tasks: • Contract management • Coordinate with the design team on aspects related to flow control and water quality systems • Coordinate with Agency on allowable treatment systems and code interpretations. • Participate in additional periodic online coordination meetings. • Perform QA/QC review Task 2 – Data Gathering and Engineering TerraVista NW will perform the following tasks: • Review studies and documentation provided by others • Perform up to one (1) additional site visits Task 3 – Preliminary Design TerraVista NW will perform the following tasks: • Review options The specific requirements for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 30% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Task 4 and 5 - Final Design TerraVista NW will perform the following tasks: • Review options for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 90% and 100% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Assumptionseach item are as follows:

Retaining Walls. A. The original scope of services did not include Engineer shall develop each retaining wall design and detailing determine the location of each soil boring needed for the foundation design of each retaining wall in accordance with the Geotechnical Manual. B. Prior to preparation of retaining wall layouts, the Engineer shall prepare a comparative cost analysis of different types of retaining walls versus roadway embankment, pavement, soil stabilization, retaining walls type, and available ROW to determine optimum selection based on economics, construction time duration, ROW encroachments (need for construction easements) and construction feasibility. C. The Engineer shall submit early in the plan preparation the retaining wall layouts to obtain approval from the State. The Engineer shall incorporate all necessary information from above referenced manuals and respective checklists into the retaining wall layouts. D. For stage construction, the Engineer shall indicate limits of existing retaining walls for removal and reconstruction, and determine limits of temporary retaining walls to be shown on the TCP. E. For projects that have retaining walls, the Engineer shall develop retaining wall layouts in the 3D corridor model. F. The approximate limits of each retaining wall shall be based on Station or length. The Engineer shall notify the State the type of retaining walls that will be used for Cut and Fill locations. Retaining wall types may include: • Spread Footing Walls (High Footing Pressure Design and Low Footing Pressure Design). The Engineer shall select a spread footing wall for fill situation when considerable room behind the walls is available for forming, constructing, and backfilling the footings and stem. The Engineer shall notify the State when the quantity is less than 1000 square feet to have as option in the plans to cast in place a spread footing wall design. This selection has to be approved to State. • Mechanically Stabilized Earth (MSE) Walls. The Engineer shall prepare the retaining wall layouts showing plan and profile or retaining walls for design by a State approved vendor. The Engineer is responsible for design of geometry and wall stability. The Engineer shall incorporate a slope of 4:1 or flatter from the existing and finished ground line elevation to the face of the retaining wall. • Concrete Block Walls (Structural and Landscape). • Tied Back Walls. • Soil Nailed Walls. • Rock Nailed Walls. • Drilled Shaft Walls. • Temporary MSE Walls. DocuSign Envelope ID: F43CDC74-DA27-4A02-AC2A-90D8CB2811D6 G. The Engineer shall select any necessary standard details from State or District’s list of standards for retaining wall items. H. The Engineer shall provide special retaining wall details which are not currently provided by the State or District’s list of standards. I. The Engineer shall provide layouts (scale 1”=100’), elevations, quantity estimate, summary of quantities, typical cross sections and structural details of all retaining walls within the project. Although the structural design will be provided by other consultants, TerraVista NW will need to prepare wall profiles to support the structural design of the walls. Also, additional time was spent in determining the extents Approximate lengths of the retaining walls as shown on the schematic are listed as below. The Engineer shall determine if any additional walls are required and viable locations within verify the project site need for and private propertylength of the retaining walls as shown on the schematic. ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇, ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇ ▇▇▇▇▇ The original scope of services was based on what was known at the time the contract was drafted and what would be anticipated for the project. As the design progressed through 30% and 90% developmentIf applicable, the complexities of a project that had significant topographic differences resulted in additional time being spent to develop grading of the roadway approaches, beyond what was originally assumedState will provide architectural standard drawings. Roadway approach grading needed to be significantly adjusted several times to try to minimize impacts to driver experience, adjacent driveways, overall earthwork, existing utilities, and so onThe Engineer shall incorporate architectural standard drawings into design details. This added effort would benefit the overall project budget and coordination with property owners. Task 1 – Project Management and Coordination TerraVista NW will perform the following additional tasks: • Contract management • Coordinate with the design team on aspects related to flow control and water quality systems • Coordinate with Agency on allowable treatment systems and code interpretations. • Participate in additional periodic online coordination meetings. • Perform QA/QC review Task 2 – Data Gathering and Engineering TerraVista NW will perform the following tasks: • Review studies and documentation provided by others • Perform up to one (1) additional site visits Task 3 – Preliminary Design TerraVista NW will perform the following tasks: • Review options The specific requirements for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 30% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Task 4 and 5 - Final Design TerraVista NW will perform the following tasks: • Review options for capturing stormwater and routing to treatment facilities. • Perform additional stormwater hydrologic and hydraulic calculations • Prepare additional supporting documentation for the stormwater drainage report • Review options for placement of retaining walls TerraVista NW will prepare 90% and 100% design documents that will also include: Plans • Add information to the drainage plans • Additional stormwater details Additional Technical Specifications Additional information on Opinion of Probable Cost Assumptionseach item are as follows: