Thrust blocks resist unbalanced pressure forces at fittings (tees/bends/caps) by mobilizing bearing against undisturbed soil. The basic thrust relationship isForce = Pressure × Areaacting on the pipe's internal cross- sectional area. DIPRA's thrust restraint guide states that internal hydrostatic pressure acts on any plane with a force equal toP times A.
From the diagram, the pipe diameter is0.200 m, so pipe area. Thrust. Required soil bearing area. Given block face area, solve. Thus the minimumis0.226 m (Option C).

Soilgrain size analysisdetermines the particle-size distribution across coarse and fine fractions. Coarse particles (sand and gravel) are sized bysieve analysis, where the sample is passed through a stack of sieves and the mass retained on each sieve is measured to build the gradation curve. Fine particles (silt and clay) are too small for practical sieving and are therefore sized usingsedimentation methods, most commonly the hydrometer test, which infers particle sizes from settling velocity in a suspension. This combined approach (sieve for coarse, hydrometer for fines) is standard in civil geotechnical testing programs because it produces a continuous particle-size distribution needed for soil classification and engineering assessment. Atterberg limits (LL/PL) areconsistency/plasticitytests for fine-grained soils-not grain size tests-so they are not the required fine-fraction method for grain-size analysis. Therefore, the correct combination for grain size analysis issieve analysis for coarse grains and hydrometer test for fine grains.

When IFC drawings state a tolerance limit, exceeding it (78 mm > 75 mm) creates anonconformancethat must be dispositioned through the proper technical authority rather than accepted informally in the field. The appropriate response is todocument the deviationand escalate it through the project's formal communication
/decision chain so engineering can assess structural implications and provide written direction (accept as-is, redesign, relocate, mitigation). Labi outlines that when significant issues arise, effective professional practice includes maintaining records and communicating through the organization's chain of command as part of a formal resolution process. Lindeburg's ethics discussion also emphasizes notifying proper authorities when decisions may adversely affect public safety and welfare-supporting escalation rather than informal acceptance. Therefore, the best approach is to submit anon-conformance reportto thedesign engineerfor review and advice.

Selecting a drawing scale is an engineering graphics task: the plan must fit within the sheet limits after allowing for borders, title block, notes, dimensions, and details. Engineering drawing practice treats scale as a proportional reduction ratio that preserves geometric similarity between the real object and the drawing. A 20 m × 30 m footprint equals 20,000 mm × 30,000 mm. At 1:50, the plotted size is 400 mm × 600 mm, which fits comfortably on a 648 mm × 917 mm sheet with room for margins and annotations. At 1:25, the plotted size becomes 800 mm × 1,200 mm, which exceeds the sheet. At 1:5, it is far too large; at 1:250, it is very small (80 mm × 120 mm), reducing readability for foundations that typically require clear dimensioning of footings, piles, grade beams, and notes. Therefore, 1:50 provides the best balance of fit and legibility for a C1 sheet, makingOption Cthe best scale choice.

Monthly progress payment certification is fundamentally based onverified quantities and percent complete for contract items installed in the field. Professional guidance on interim valuations emphasizes that periodic payments are established fromsite measurement/valuationof work completed, then certified by the contract administrator (or equivalent). That process requires a reliable field record of installed work-typically maintained daily by inspection staff-showing item-by-item progress, quantities, locations, and dates. Among the options, aninspector's daily progress recordis the document specifically intended to track completed work in a form that supports valuation, whereas a diary is less structured, packing slips only show deliveries (not acceptance/installation), and safety meeting records relate to OH&S rather than payment entitlement.
Therefore, the best supporting record for producing a progress payment certificate is theinspector's daily progress record, because it ties payment to measured/verified construction progress as required for interim certification practices.