2018-01-23_REVISION - M1977348 - Laserfiche WebLink

Home Browse Search

Request for Technical Revision — US 287 Geotechnical Investigation B-6 40.6723,-105.1467 40 HSA/Coring B-25 40.6725,-105.1466 40 HSA/Coring P-5 40.6735, -105.1471 10 HSA B-7 40.6779,-105.1485 30 HSA P-6 40.6801, -105.1493 10 HSA B-8 40.6841,-105.1502 40 HSA/Coring P-7 40.6871,-105.1507 10 HSA P-8 40.6898,-105.1509 10 HSA B-9 40,6916,-105.1510 40 HSAICoring B-10 40.6945,-105.1512 50 HSA/Coring P-9 40.6970,-105.1513 10 HSA P-10 40.6998,-105.1511 10 HSA P-11 40.7024, -105.1507 10 HSA P-12 40.7052,-105.1505 10 HSA B-11 40.7085,-105.1503 40 HSA/Coring P-13 40.7113,-105.1496 10 HSA P-14 40.7141,-105.1492 10 HSA B-12 40.7164, -105.1490 60 HSA/Coring B-13 40.7168,-105.1499 60 HSA/Coring B-14 40.7189,-105.1507 60 HSAICoring I Borings designated with a "P" refer to shallow pavement subgrade borings; borings designated with a "B" refer to deeper foundation borings. 2 Maximum boring depths are based on CDOT Geotechnical Design Manual. Bedrock is anticipated to be shallower, but a minimum of 10 feet of core recovery is required. 3 Hollow -stem auger (HSA) advances continuous flight steel casing with a cutting head, and requires no air or water. Coring consists of HQ3 (3.375 -inch dia.) rock core recovery systems, and requires clean water (estimated <100 gallons for 10 -ft coring requirement). 4 Barings B-22 and B-23 are being advanced from atop the southern spoil piles, thus the added drilling depth to get to 10-20 feet below planned roadway subgrade at these locations (relatively shallow holes despite the greater total drilling depth). A limited number of additional borings will be needed at specific structure locations along the proposed alignment/existing haul road in support of final design (i.e., one bridge location, various box culvert/drainage structures). These additional borings will follow the same drilling and completion procedures outlined herein. Final design borings are intended to meet the investigation spatial frequency requirements outlined by CDOT, and are therefore similar in both method and maximum depth to the preliminary borings shown in Table 1. Final design borings for structures will be located in the approximate vicinity of the "B" designated borings listed in Table 1.