Bellevue Tech Tower Pit Safe

BELLEVUE, WA-Around several Puget Sound publications, news reports had been circulating that the pit at the site of the Bellevue Technology Tower, construction of which has been stopped mid-course, could pose a threat to surrounding areas. The city of Bellevue had been quoted as having concerns sufficient enough to warrant its hiring of experts to determine the extent of the threat, including the possible settling of adjacent roads. However, both the project’s geotechnical engineer and Bellevue’s plans examination supervisor tell GlobeSt.com the hype is for naught.

In building the Tower’s record-breaking underground base, “temporary” soil nails were used to hold the earth in place while the permanent (concrete) underground structure was completed. News reports have stated that the rebar used for those temporary soil nails could begin corroding within a year of their insertion, leaving the area vulnerable to settling or collapse if the permanent structure is not completed soon.

The problem of time lies in the financial and legal situations that have developed around the project. The soil nailing was completed in the early part of this year, but construction was halted in May when E&H Properties (owned by Eugene Horbach) lacked sufficient funds to make payments to the general and sub-contractors working on the would-be 20-story tower. Since, a flurry of suits has been spawned by E&H, DPR and the subs, leaving most to wonder when and if the issues might be resolved. And, the gigantic pit has stirred imaginations and concerns about what might happen if resolution lies a long way off.

Gregg Schrader, the city’s plans examination supervisor, tells GlobeSt he is somewhat dismayed by the way his words have been construed in print. In speaking with GlobeSt, Schrader was eager to clarify his previous comments, saying “We have consultants including Golder (the project’s geotechnical engineer) and other geo-engineers that regularly review projects for us. We have looked to the consultant that did the review on this project originally, as well as to Golder. We have received no indication from either that there is any immediate concern.” Schrader continues, “Hopefully this will be resolved soon and the project will proceed in some manner. We’d certainly like to see that.”

David Cotton is Golder’s geotechnical engineer who did the design work on the Technology Tower. In speaking with GlobeSt, he was quick to stress, “At this point there is no concern for the integrity of the ground support system that’s currently in place.” Cotton explains that there are two ways of measuring the life of the soil nails: the length of time Golder is legally responsible for the work’s integrity, and the realistic life, which he says is more like “five years, perhaps as much as ten or 15 without substantial movement, notwithstanding a major earthquake.”

Speaking of quakes, Cotton says the nailing has already stood up to one reasonably tough test drive. At the time of the Nisqually Quake on February 28th, workers had just finished installing the rebar soil nails but they had barely started putting on the concrete face of the wall. “The crane was swaying, and those at the bottom of the pit were having quite an exciting moment,” says Cotton, continuing, “There was raw, wet concrete on the face, and none of it fell off. We were all surprised at how it held up.” Bottom line, Cotton expects that any potential threat would be quite a ways down the road, hopefully more than enough time for E&H and all the Technology Tower parties to find solutions and move forward.