UPDATED: Sunrise Hue Apartments Most Innovative In Redmond

The parcel rests on a seismic hazard zone over the shallow aquifer. -- Geotechnology Engineer's report.

The proposed building is a six-story, mixed-use apartment building, only a five minute walk to light rail. It is located at the intersection of 164th and NE 85th Street.  A single family home, vacant lot (Brown Bag restaurant)  dentist office and strip mall (Herfy's Burger) across from 164th are on the site. The building is designed with a hint of orange in concert with the name "Sunrise Apartments."  This is a big breakthrough for Redmond from mustard colors; the Design Review Board still challenged them on the color! 

It consists of 1,991 sf of commercial retail space at the ground level with varying amenity spaces throughout. On levels two through six, there are 93 residential units. 83 internal parking stalls are provided at the ground level within the building with a three level car stacker system, as well as an additional subterranean level with additional parking spaces. 

One of the common open space features is located on the roof top. (see video.)  The deck itself features group seating, four Magnolia trees, Italian Cyprus, raised planters, a turf lawn gathering area, an outdoor kitchen, a green wall system, and a 42” height seating bar with canary lights draped over the central seating area.  The supposed "eclectic" SE Redmond Marymoor neighborhood could learn from this innovative developer.  

On the street level, the creative plaza design provides a sense of reprieve for pedestrians by incorporating seating areas within the vegetation and trees.  The building is set-back significantly providing wide sidewalks (see video.)

Of note, the interesting design of a double height indoor resident open space referred to as the “Sky Lounge” is located at the 6th level. It provides visual interest for the public while also providing a unique indoor recreational space for the residents, filled with natural light and broad views of the skyline.

Pictures and details at this link.

--- Design Review Board memo, 2/21/2021

     Opinion, Yoder

Read More for GeoTechnical Report.  (This project is located in Seismic Hazard Area.) 

In order to mitigate the potential for liquefaction induced settlement damage to the structure and coupled with considerations for seasonal high groundwater level being higher than the proposed finished floor elevation, we recommend supporting the building on a mat foundation.  Building inspector.

The watertight below grade parking level will be subjected to hydrostatic uplift forces when the groundwater level outside the structures is higher than the base of the mat slab. For design against hydrostatic uplift, a design groundwater elevation of 34 feet should be assumed. Structures should be designed to resist this upward force and to prevent possible heave and cracking of foundations and slabs. The weight of the structure and the uplift capacity of the shoring system around the basement perimeter may be used to resist uplift forces.  

It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and their use in guiding our engineering judgment. 

The descriptions of groundwater conditions and depths are approximate. 

The design team should be aware that groundwater levels are not static. Groundwater levels will vary depending on the season and precipitation levels. Groundwater levels are typically higher in the wet season, typically October through May. 

The entire site is located in a City of Redmond mapped Seismic Hazard Area

Based on the subsurface conditions, there is the potential for soil liquefaction below the site, specifically in the loose to medium dense sand encountered deeper than 20 feet below existing grade. The estimated potential liquefaction induced settlement may be as much as about 6 inches. The earthquake-induced settlement should be quite consistent, since the soil conditions at the site are quite uniform. 

The allowable bearing pressure may be increased by 1/3 for transient loading such as wind or seismic loads. Reinforcing steel and post tensioning requirements for the mat foundations should be designed by the project structural engineer to withstand hydrostatic uplift.

MITIGATION:  We anticipate the building design will follow the 2015 International Building Code (IBC). The International Building Code (IBC) seismic design section provides a basis for seismic design of structures.  Conformance with the 2015 IBC, which specifies a design earthquake having a 2% probability of occurrence in 50 years (return interval of 2,475 years), and the 2008 USGS seismic hazard maps.

The gravely soil in Redmond will ravel and slough between the shoring bays during excavation. In order to reduce the amount of raveling, it may be necessary to reduce the depth of the shoring lifts. We recommend voids behind the lagging be backfilled with CDF. Because the site is located over the Redmond Alluvial Aquifer, untreated timber should be used for lagging.

If it is planned to re-use the site soils as structural fill, an environmental consultant should be retained to test the soils to verify the soils meet the requirements of RMC 15.24.095 Wellhead and Groundwater Protection Performance Standards.

In no case should the demolition materials be used as structural fill or mixed with material to be used as structural fill. 

Generally, loosely compacted soils are a result of poor construction technique or improper moisture content

Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope.

--  Siew Tan, P.E.

    PanGEO, Inc.

    12/11/2020