Other than the tradeoff for less excavation and backfill versus the shoring box rental for Exercise 7, what are some additional complications and potential costs an estimator might consider for a slope cut of this magnitude?

Data from exercise 7

The contractor installing the sewer pipe in Figures 16.3 and 16.4 chose a moveable trench shoring system over a 1:1 slope cut excavation. Calculate the contractor’s overall savings for this approach utilizing the excavation conversion process and pricing discussed with structural excavation in Chapters 6 and 10. Assume the native soils are sufficient for backfill.

Figures 16.3

Figure 16.4

 

Transcribed Image Text:

Tri-County Conveyance Pipeline - Estimate Bid Item: 4- Install 18" PVC Sanitary Sewer Quantity Description Rate Foreman 2 Flaggers 3 Operators Laborers 123212 2 1 2 1 1 2 1 1 1 1 CREW AND EQUIPMENT Hourly Labor Cost per Shift Pipelayer Truck Drivers Excavator Wheeled Loader Tool Truck Pickup 55 34 50 35 42 49 Dump Trucks 70 KW Gen w/Pumps Compactor 440 544 1,200 560 336 784 High Country Construction Equip Cost per Shift Subtotal Labor Cost/Shift Add Labor Burden @ 55% of Labor Total Labor Cost/Shift 800 500 400 200 150 120 90 Shift Total 440 544 1,200 560 336 784 3,864 2,125 $5,989 800 500 400 200 150 120 90 Total Equipment/Shift 2,260 Total Labor and Equipment/Shift 8,249 Number of Shifts 9 Activity Labor and Equipment $74,241 Scope: Install 1,600 LF of 18" PVC Sanitary Sewer CONSTRUCTION AND PERMANENT MATERIALS Material 18" PVC Pipe Pipe Bedding Backfill (native) Shoring Quantity Unit Unit Price Total Price 1,600 LF 625 TN 0 TCY 2 WKS SUBCONTRACTORS Unit Subcontractor Quantity Closed-Circuit Television Test 1,600 Activity Install 18" Sanitary Sewer Pipe 1,600 LF @ 200 LF/Shift Existing Utilities 400 Total Materials ACTIVITY DURATION Labor and Equipment Cost Materials Cost Subcontractor Cost Total Activity Direct Cost 28 8 LF 3 Total Subcontractor Total 74,241 50,600 4,800 $129,641 Unit Price Total Price Shifts TOTAL ACTIVITY DIRECT COST 8 9 44,800 5,000 0 800 $50,600 4,800 $4,800