AgdaPkt 2010-06-14 - Laserfiche WebLink

Browse Search

7.A Page 41 Attachment C Redwood City's questions and concerns related to the High Speed Rail Authority's Preliminary Alternatives Analysis Report There is no alternative in the Preliminary AA Report showing Caltrain in a deep bore tunnel. Please state the reason for this. Was this alternative dismissed due to cost and station construction constraints, or for other reasons? What are the advantages and disadvantages of covered trenches compared to tunnels? What are the criteria used to distinguish between the two? How does a covered trench compare to a deep tunnel, in terms of ventilation requirements (including length of the tunnel or trench)? How do potential excavation depth and the construction cost of a stacked, cut and covered trench compare to a 2-track deep bore tunnel under a 2-track cut and covered trench? Would the lower two tracks in the stacked trench require the same ventilation/life/safety requirements of a deep tunnel? Please describe. Please confirm the typical supporting column spacing and the beam depthMto-span ratio for the aerial viaduct option. At Redwood Junction in Appendix Subsection 5.11 the Preliminary AA Report provides only for the at-grade option. If the tracks were depressed, how far would the elevation of the spur tracks have to be adjusted? Would this adjustment affect the right-of-way of the spur tracks and the neighborhoods which the spur tracks traverse? If the grade adjustment of the spur tracks can be achieved, can Caltrain tracks be depressed at this location? Can HSR be located in a trench in Appendix Subsection 5.1? In terms of stitching, if HSR is in a trench at Appendix Subsection 5.2, what is the feasibility of placing it in a trench in Appendix Subsections 4C, 4D, and 5.1? Appendix Subsection 4.3 indicates it is possible to depress Woodside Road to accommodate the elevated crossing at this location. This could result in enormous construction costs and community impact. Please provide construction cost estimates related to a potential Woodside Road underpass, and the anticipated impact to the community. Please outline the pros and the cons of designing train tracks that are elevated above the existing Woodside Road overpass without depressing the roadway. Please confirm whether four sideMby-side tracks may be shared by HSR and Caltrain during normal operation. What was the reason for eliminating a 4-track at-grade option in Appendix Subsection 4- 3? Did this relate to the right-of-way required at the street crossing grade separations, the narrow track right-ofMway itself, or other considerations?