Category Archives: Announcement

Seattle DR on Pin Piles

Hello everybody!  Susan Chang of SDCI announced at our October DM that they are looking into revising their existing Directors Rule on pin piles (DR2009-10) to include Push Piers. They would like the ASCE Geotechnical group to help revise and give guidance for this document.

Brendan Cioto (BWC@shanwil.com) offered to help organize the committee for this effort. Please get in touch with him if you would like to be involved.

Spring Seminar 2018 Topic Survey

Hello everybody!  We will soon be selecting a topic for the 2018 Spring Seminar. Your input is important to us. Please take the following survey to help us better provide an educational and useful seminar for you next spring.  Any comments, concerns, or questions are appreciated. Thanks!

Survey Link

President-Elect Steve Johnson (Stephen.Johnson@sixense-group.com) is this year’s Seminar Chair.  Steve will be looking for volunteers to serve on the steering and planning committees.  If you want to get involved please contact Steve.

FHWA

Please consider joining us for another activity the week of May 22.  Several FHWA Geotechnical leaders will be in Seattle on Monday May 22, 2017 and will provide an overview of the FHWA Geotechnical program, technical assistance projects, and FHWA geotechnical research. Registration is now open (no cost) but please RSVP so we have a headcount.

FHWA Geotechnical Program

2017 Hennes Lecture at University of Washington

The GIGGS group at the University of would like to invite everyone to join them at their annual Hennes Lecture.  It is being held on Friday May 26th from 4pm-7pm on the UW campus. The presentation will be given my Jonathan Stewart, Chair of Civil Engineering at UCLA.

Friday, May 26
Presentation: 4:00 – 5:00
Reception: 5:00 – 7:00 (snacks provided, and drinks available for purchase)
The lecture is on the UW campus, in the Husky Union Building (HUB) Room 145
The event is free to attend and RSVP is not needed.
Contact: Shane Joseph Markus markussh@uw.edu

Title:
Site response uncertainty and its implications for seismic risk characterization

Abstract:
Along with source and path effects, site response analysis is a vital component of earthquake ground motion characterization. Ground motion prediction equations (GMPEs) include terms for modeling site response that are based on simple metrics of site condition, such as the time-average shear wave velocity in the upper 30 m (VS30). Because site terms in GMPEs are derived from global databases, and are based on incomplete information on site conditions, their predictions represent average levels of site response conditional on VS30. Such predictions are referred to as ergodic.

Actual site response at a given site is likely to differ from this global average. Viewed in this context, the actual site response for a particular site and intensity measure is the sum in log units of the ergodic estimate from a global model and a (generally unknown) site term (denoted hS). If the level of site-specific error (hS) can be identified and used to adjust the ergodic model, the ground motion analysis is more accurate (i.e., bias is removed) and the dispersion of the predicted ground motions is reduced. Therefore, site-specific evaluations of site response are useful and will often reduce mean hazard levels at long return periods (due to dispersion reduction), although uncertainty in the site response is considered in an epistemic manner.

Important questions pertaining to this process include how should these evaluations be performed, how reliable are the resulting site response estimates, and how can the results be used in a probabilistically rigorous manner as required for hazard- or risk-based applications?

With this in mind, the presentation will cover:

  1. The physical processes responsible for site effects;
  2. The manner by which these processes are (or are not) reflected in relatively generic site factors used in GMPEs and in building codes;
  3. Effectiveness of site-specific geotechnical ground response analyses to estimate site effects;
  4. Recommended procedures for evaluating site-specific site response and its implementation in hazard/risk characterization for critical facilities.

 

2017 Stanley D. Wilson Memorial Lecture

Shannon & Wilson, Inc. and the University of Washington’s Department of Civil and Environmental Engineering are pleased to present the 2017 Stanley D. Wilson Memorial Lecture. Steve Kramer will discuss “Time and Soil Liquefaction” on Thursday, March 23 at 5:30 in Room 389 of Mary Gates Hall on the University of Washington Campus. Please R.S.V.P. by March 16th at rsvpsea@shanwil.com or (206) 695-6743. The event is free to the public.

2017 Wilson Lecture Postcard

 

Groundhog Newsletter

Punxsutawney Phil saw his shadow this morning so apparently we are in for 6 more weeks of winter, if it stays as clear and gorgeous as today was in Seattle, I’m not sure that is anything to complain about.  Here is some light reading to occupy your time during this winter season.  We are pleased to present out 2017 Groundhog! Happy Reading!

2017Groundhog