Pacific Highway – Constructed over Nambucca Floodplain – Engineering Assessment Answer

By
Responsive Centered Red Button

Need Help with this Question or something similar to this? We got you! Just fill out the order form (follow the link below), and your paper will be assigned to an expert to help you ASAP.

Order Form

Engineering Assessment Answer
TASK:
1. Introduction
A section of the Pacific Highway upgrade is proposed to be constructed over Nambucca Floodplain. Situated in the Mid North Coast region of New South Wales, the 2.5 km wide Nambucca Floodplain is on the southern side of the Nambucca River near Macksville. The site is generally underlain by soft Holocene alluvial clay to a depth of about 15 m, followed by approximately 5 m thick soft/firm Holocene alluvial sandy clay, and about 10 m thick Pleistocene sandy deposits.
There are two flood relief structures associated with the embankment construction at Nambucca Floodplain, namely Floodplain Bridge 1 (FPB1) at Ch 50,200 m – Ch 50,265 m and Floodplain Bridge 2 (FPB2) at Ch 50,955 m – Ch 51,015 m, as shown in Figure 1 and 2 respectively. This is a 4-member team project. Each team will be assigned one of the bridge approaches (northern or southern) at one of the two bridges (FPB1 or FPB2).
Engineering Assignment
Civil Engineering Assignment
Engineering Civil Assignment
The cross-section of the approach embankment is shown in Figure 3. The height of the approach embankments to these bridges ranges from 3.2 to 4.6 m. For the purpose of this design project, consider that there are 12 possible longitudinal profiles of the 50 m long approach embankment, earmarked by embankment heights H 1 and H 2 as shown schematically in Figure 4 and tabulated in Table 1. Each 4-member design team will also be assigned one of the approach embankment profiles to design.
Engineering Assignment
Engineering Assignment
The suitability of various ground improvement techniques have been considered in developing the design solution. These ground treatment options include light weight fill (bottom ash) and ultra-light weight fill (geofoam), surcharging with / without wick drains, stone columns, deep soil mixing, controlled modulus columns, piled embankments, vacuum consolidation, and electro-osmosis. Based on the assessment and also the experiences from past Pacific Highway projects with similar ground conditions, it is considered that preloading and surcharging are appropriate for the present soft ground conditions encountered. For
the bridge abutment locations where preload duration could adversely affect the constructionprogramme, it has been advised by the contractor to include prefabricated vertical drains (PVDs) to accelerate the soft soil consolidation process.
2. Scope of Design Work
All students are to be divided into 48 groups, each will be assigned a group ID. Each group is to carry out soft ground treatment design for a bridge abutment/approach using preload with surcharge and PVDs. To allow the embankment fill to be placed with an adequate factor of safety against stability.
Engineering Civil Assignment
Engineering Assessment Help
Civil Engineering Assessment Answer
Performance CriteriaThe design requirements pertinent to the present soft ground treatment designs are listed
below. Requirements in relation to the design for settlement:

The ground treatment proposed herein has been designed for the use of ‘flexible’ pavement type as per the Tender Design. The design criteria for the ground treatment design suitable for flexible pavement as per Appendix 11, SWTC are:
Limit the total Post Construction Settlement (PCS) at the bridge approach slab to a maximum of 50 mm over 40 years.
For locations greater than 50 m from the bridge abutment, limit the total PCS to a maximum of 200 mm for flexible pavements over 40 years.

Except for bridge approach slabs, limit the differential settlements, in any direction, to a maximum of 0.3% over 40 years.

Clause 13.3.8 (f) of Appendix 13 of the SWTC requires that a minimum nominal live load of 10kPa to be allowed for in the assessment of settlement of soil and slope structures.

Requirements in relation to the design for embankment stability:

Clause 13.3.8 of Appendix 13 of the SWTC requires that the embankment on Poor Ground to be designed in accordance with BS8006 (ground which consists of firm or weaker soil layers as defined in Table A4 of Australian Standard AS 1726:
Geotechnical Site Investigation). In addition to the loads specified in BS8006, earthquake loading with an annual probability of exceedance of 1 in 500 must be included in the design.

Clause 13.3.8 (f) of Appendix 13 of the SWTC requires that a minimum nominal live load of 20kPa to be allowed for in the assessment of the stability of the spill through batter.

In accordance with Clause 13.3.8 (d) of Appendix 13 of the SWTC, the targeted factor of safety (F.O.S) for unreinforced soil slopes are:

Long term F.O.S. 1.5 minimum; and Short term F.O.S. 1.2 minimum.

The design ground water level shall be determined in accordance with Clauses 13.3.8
(e) (vii) and 13.4.1(e) of Appendix 13 of the SWTC.

5. Site Specific Geology and Geotechnical Model5.1
Floodplain Bridge 1 (FPB1)
The ground conditions at the bridge site are generally up to about 3 m thick soft/firm Holocene clay (Unit 2a), overlying about 1.5 m thick stiff Pleistocene clay (Unit 3a). This is underlain by up to about 2.5 m thick residual soil over weathered Phyllite bedrock. With reference to Figure 1, a 60 m wide paleo-channel has been identified to traverse the fill
embankment at about 150 m to the south of FB1. Two CPT soundings (CPT10 and CPT11), and one borehole (BH102) conducted have registered up to about 9m thick very soft to firm Holocene alluvium, whereas data at a distance of ±50m away (such as CPT09 to the south and CPT172, CPT12 to the north) have registered a much thinner soft soil thickness of only up to about 2m. These geotechnical investigation data obtained, in conjunction with the vegetation pattern observed during a site visit and from the aerial photographs (e.g. the eucalyptus paperbark trees are distinctly shorter in the area of deep soft soil), have indicated the presence of a potentially 60 m wide paleo-channel traversing the proposed fill embankment at a skew angle of about 40? from the main alignment.
5.2
Floodplain Bridge 2 (FPB2)
For Floodplain Bridge 2 (Figure 2), the geological conditions between the southern and the northern abutments differ markedly. As can be seen from the geotechnical longitudinal section provided in Figure 5, the base of the soft Holocene soils (Unit 2a and Unit 2b) dips in the northern direction from about RL-5.5m (6.5m thickness) at the southern abutment to
about RL -21.5m (22.5m thickness) at the northern abutment.
The Holocene deposits are underlain by stiff to very stiff Pleistocene clay (Unit 3a) of about 15m thickness at the southern abutment and about 5m thickness at the northern abutment. Unit 3b/3c clayey sand and generally sand was also encountered under the Holocene deposits further to the north and away from the bridge site.
The Pleistocene strata are currently inferred to be underlain by extremely low to low strength Intrusive Volcanics (Unit 8b/c) at the southern abutment and high to very high strength Hornfels (Unit 7e) at the northern abutment. Existing monitoring wells installed in the vicinity of the bridge area (4BH037 and 4BH038) indicate that groundwater is near the ground surface.
Engineering Civil Assignment
6. Soil Compressibility
Each group of students shall derive their own compressibility values of the Holocene soft soils (i.e. the compression ratio, CR, the recompression ratio, RR, and the normally consolidated creep strain rate, c) from the oedometer tests listed in Table 3.
Engineering Civil Assignment
Effective strength parameters
All groups shall derive their own effective strength parameters of the Holocene soft soils based on the consolidated undrained (CU) triaxial tests listed in Table 6.
Engineering Civil Assignment
This Engineering Assessment has been solved by our Engineering experts at TVAssignmentHelp. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+ Students in Australia, UK & US by helping them to score HD in their academics. Our Experts are well trained to follow all marking rubrics & referencing style.

Be it a used or new solution, the quality of the work submitted by our assignment experts remains unhampered. You may continue to expect the same or even better quality with the used and new assignment solution files respectively. There’s one thing to be noticed that you could choose one between the two and acquire an HD either way. You could choose a new assignment solution file to get yourself an exclusive, plagiarism (with free Turnitin file), expert quality assignment or order an old solution file that was considered worthy of the highest distinction.

How to create Testimonial Carousel using Bootstrap5

Clients' Reviews about Our Services