Q1 50M Compulsory design Concrete deterioration, brick masonry, pavement design, railway gradient, plane table surveying
(a) (i) Briefly explain the deterioration of concrete caused by leaching action, and (ii) chemical interaction. (10 marks)
(b) What are the general precautions to be observed while constructing a brick masonry work? Briefly explain with the help of neat sketches where possible. (10 marks)
(c) A cement concrete pavement of thickness 20 cm, has two lanes of 7·2 m with a longitudinal joint. Design the tie bar. Assume allowable working stress in tension for steel as 1400 kg/cm² and bond strength with concrete as 18 kg/cm². (10 marks)
(d) What would be the gradient for a M.G. track when a grade resistance together with curve resistance due to a curve of 6° shall be equal to the resistance due to ruling gradient of 1 in 200? (10 marks)
(e) What do you understand by orientation of Plane table? Discuss various methods of orienting the Plane table. (10 marks)
हिंदी में पढ़ें
(a) (i) निषालन क्रिया, तथा (ii) रासायनिक अन्तःक्रिया के द्वारा कंक्रीट के अवक्षय की संक्षेप में व्याख्या कीजिए। (10 अंक)
(b) एक ईंट चिनाई कार्य का निर्माण करते समय क्या सामान्य सावधानियाँ बरती जाती हैं? जहाँ सम्भव हो स्वच्छ रेखाचित्रों की सहायता से संक्षेप में व्याख्या कीजिए। (10 अंक)
(c) एक 20 cm मोटी सीमेंट कंक्रीट कुशिम में अनुदैर्ध्य जोड़ के साथ 7·2 m की दो लेन हैं। बंधन छड़ का अभिकल्पन कीजिए। इस्पात के लिए तनन में अनुज्ञेय कार्यकारी प्रतिबल 1400 kg/cm² और कंक्रीट के साथ बंधन सामर्थ्य 18 kg/cm² मान लीजिए। (10 अंक)
(d) एक एम.जी. रेलपथ के लिए प्रवणता क्या होगी यदि 6° के वक्र के कारण वक्र प्रतिरोध के साथ प्रवणता प्रतिरोध, 200 में 1 की नियंत्रक प्रवणता के कारण प्रतिरोध के बराबर हो? (10 अंक)
(e) प्लेन टेबल के अभिविन्यास से आप क्या समझते हैं? प्लेन टेबल के अभिविन्यास करने की विभिन्न विधियों की विवेचना कीजिए। (10 अंक)
Answer approach & key points
This multi-part question requires a balanced approach across theoretical explanations, numerical design, and practical applications. Allocate approximately 20% time to each sub-part: (a) explain leaching and chemical attack mechanisms with examples like sulfate attack in coastal Gujarat; (b) describe brick masonry precautions with sketches showing frog placement and bonding patterns; (c) design tie bars showing complete calculations for spacing and diameter; (d) solve the railway gradient problem using IRC formulas for curve compensation; (e) explain plane table orientation methods with field procedure diagrams. Begin with concise definitions, present numerical parts with clear formulae and substitutions, and conclude with practical implications for Indian construction conditions.
- (a) Leaching: explains dissolution of Ca(OH)₂ in flowing/pure water, increased permeability, reference to IS 456 limits; Chemical interaction: covers sulfate attack (ettringite formation), chloride-induced corrosion, alkali-aggregate reaction with Indian examples like Thane creek structures
- (b) Precautions: soaking bricks, proper mortar consistency (1:6 for normal, 1:4 for exposed), English/Flemish bond patterns, frog upward placement, 10-12mm joints, curing; sketches showing queen closer, header-stretcher arrangement
- (c) Tie bar design: calculates frictional force (WLf/2), steel area required (Aₛ = F/σₛₜ), bond length check (L = F/πdτ_bd), final specification of diameter, spacing, length with IRC:58 provisions
- (d) Railway gradient: applies curve resistance formula (0.04° for BG, 0.03° for MG), equates grade resistance + curve resistance = ruling gradient resistance, solves for compensated gradient
- (e) Orientation: defines as making table parallel to ground line; methods—(i) trough compass (magnetic), (ii) back-sighting (geometric), (iii) resection (three-point/Bessel's method); compares accuracy and field conditions for each
Q2 50M solve Equipment economics, flexible pavement design, spot speed study
(a) A construction company is planning to purchase an excavation equipment for operating a borrow soil pit that will last 5 years. The soil can be excavated by equipment 'A' or equipment 'B'. Equipment 'A' has an initial cost of ₹ 1·32 lakh and will have no salvage value at the end of the project. Equipment 'B' has an initial cost of ₹ 0·21 lakh. However, to provide the same capacity, 2 numbers of equipment 'B' are required and their operating cost per year together (for 2 numbers of equipment 'B') will be ₹ 0·18 lakh more than the equipment 'A'. Normal service life for equipment 'B' is 3 years with zero salvage value but a 2-year-old equipment 'B' can likely be sold for ₹ 0·05 lakh. If the interest rate is 15%, which equipment (equipment 'A' or 2 numbers of equipment 'B') should be preferred to purchase from the present worth point of view? The estimated salvage value for equipment 'B' must be included as a cash inflow at the end of year 5. (15 marks)
(b) Design a flexible pavement for a two-lane undivided carriageway using the following data: Subgrade CBR value = 8%, Lane distribution factor = 0·5, Design Life = 15 years, Planning and Construction period = 1·5 years. Present commercial traffic is as under: Bus (Gross Wt. 15T, 200 vehicles/day, Front Axle – Single, Rear Axle – Dual, Growth Rate 4%), Truck (Gross Wt. 20T, 1512 vehicles/day, Front Axle – Single, Rear Axle – Tandem, Growth Rate 8%). As per IRC 37, 2018 the following pavement composition is desired for CBR of 8% subgrade corresponding to different Design traffic: [Table showing Design Traffic (msa) vs pavement layers]. (15 marks)
(c) The following data were obtained from the spot speed study carried out at a city road. Suggest (i) Speed limit for regulation, (ii) Speed to check geometric design elements, (iii) Lower speed group causing congestion. [Table showing Speed Range (km/hr) vs No. of Vehicles]. (15 marks)
हिंदी में पढ़ें
(a) एक निर्माण कम्पनी एक मिट्टी खदान के प्रचालन के लिए एक खुदाई उपकरण के क्रय की योजना बना रही है जो 5 वर्ष तक रहेगा। मिट्टी उपकरण 'A' या उपकरण 'B' के द्वारा खोदी जा सकती है। उपकरण 'A' की प्रारंभिक लागत ₹ 1·32 लाख है तथा परियोजना के अंत में निस्तारण मूल्य कुछ भी नहीं होगा। उपकरण 'B' की प्रारंभिक लागत ₹ 0·21 लाख है। यद्यपि समान क्षमता के लिए 'B' के दो उपकरणों की आवश्यकता होगी तथा उन दोनों की प्रचालन लागत प्रति वर्ष ('B' के दो उपकरण) उपकरण 'A' से ₹ 0·18 लाख अधिक होगी। उपकरण 'B' की सामान्य सेवा आयु 3 वर्ष है और निस्तारण मान शून्य है लेकिन एक 2 वर्ष पुराना उपकरण 'B' ₹ 0·05 लाख में विक्रय किया जा सकता है। यदि ब्याज दर 15% है, तो कौन-से उपकरण को (उपकरण 'A' या 2 संख्या में उपकरण 'B') वर्तमान मूल्य के दृष्टिकोण से क्रय करने हेतु वरीयता देनी चाहिए? उपकरण 'B' का अनुमानित निस्तारण मूल्य 5 वर्ष के अंत में नकदी अंतवाह के रूप में शामिल किया जाना चाहिए। (15 अंक)
(b) निम्नलिखित आँकड़ों का उपयोग करते हुए एक अविभाजित दो-लेन मार्ग के लिए एक नम्य कुशिंग का अभिकल्पन कीजिए: सबग्रेड का सी.बी.आर. मान = 8%, लेन वितरण गुणक = 0·5, अभिकल्पन आयु = 15 वर्ष, परिकल्पन तथा निर्माण अवधि = 1·5 वर्ष। वर्तमान व्यावसायिक ट्रैफिक निम्न प्रकार है: बस (सकल भार 15T, 200 वाहन प्रतिदिन, अग्र धुरी – एकल, पश्च धुरी – दोहरी, वृद्धि दर 4%), ट्रक (सकल भार 20T, 1512 वाहन प्रतिदिन, अग्र धुरी – एकल, पश्च धुरी – अग्रपश्च (टैन्डम), वृद्धि दर 8%)। IRC 37, 2018 के अनुसार, सबग्रेड 8% के लिए विभिन्न अभिकल्पित ट्रैफिक के अनुसार निम्नलिखित कुंडिम संयोजन अपेक्षित है: [सारणी दिखाते हुए अभिकल्पित ट्रैफिक (एम.एस.ए.) बनाम परतें]। (15 अंक)
(c) एक शहर की सड़क पर किए गए स्थानिक गति अध्ययन से निम्नलिखित आँकड़े प्राप्त किए गए। सुझाइए (i) नियमन के लिए गति सीमा, (ii) ज्यामितीय अभिकल्प घटकों की जाँच के लिए गति, (iii) संकुलन करने वाले निम्न गति समूह। [सारणी दिखाते हुए गति परास (km/hr) बनाम वाहनों की संख्या]। (15 अंक)
Answer approach & key points
Solve all three sub-parts systematically: (a) Calculate present worth of costs for Equipment A vs two Equipment B using 15% interest rate, accounting for replacement cycle and salvage value; (b) Design flexible pavement using IRC 37:2018 by computing cumulative standard axles (msa) and selecting layer thicknesses from the provided table; (c) Analyse spot speed data to determine 85th percentile speed for regulation, 98th percentile for geometric design, and identify congested speed groups. Allocate approximately 35% time to part (a) due to complex replacement analysis, 35% to part (b) for detailed traffic calculations, and 30% to part (c) for statistical interpretation. Present each part with clear headings, formulae, calculations, and final recommendations.
- Part (a): Correct application of present worth factor (PWF) at 15% for 5 years; Equipment A: single investment with annual operating costs; Equipment B: initial purchase plus replacement at year 3 with salvage of old equipment, higher combined operating costs, and final salvage value at year 5 included as cash inflow
- Part (a): Proper handling of Equipment B's replacement economics - buying new unit at year 3 while selling 2-year-old unit for ₹0.05 lakh, and recognizing that 2 units of B operate throughout
- Part (b): Correct calculation of design traffic using F=365, lane distribution factor 0.5, vehicle damage factor (VDF) for buses and trucks as per IRC 37:2018, growth factors (4% and 8%), and construction period of 1.5 years
- Part (b): Accurate computation of cumulative standard axles in msa and selection of appropriate pavement layer thicknesses from IRC 37:2018 table for CBR 8% and calculated design traffic
- Part (c): Statistical analysis of spot speed data - calculation of cumulative frequency distribution, identification of 85th percentile speed for regulatory speed limit, 98th percentile for geometric design checks, and determination of lower speed group causing congestion (typically below 15th percentile or modal speed range)
- Part (c): Proper presentation of frequency distribution table and cumulative percentages to justify speed recommendations with clear reasoning for each decision
Q3 50M design Highway engineering, surveying, and project management
(a) A two-lane State Highway in plain terrain, with cutting section having camber of 2·0%, negotiates a curve of radius 480 m. Design superelevation and explain the process of attaining designed superelevation with the help of neat sketches. 15 marks
(b) (i) The following consecutive readings were observed, on a continuously sloping ground, with the help of a 4·0 m staff and a dumpy level. If the reduced level of first point is 99·000 m, calculate the level of last point by entering the readings in level book. Also apply the usual checks. 10 marks
3·815, 2·500, 1·335, 2·980 and 0·800 m
(ii) The maximum quantity of water to be discharged by the side drains on both sides of a highway section is 1·8 m³/s. Design rectangular side drains for the following conditions. Both drains carry equal discharge.
Maximum permissible velocity of flow = 0·8 m/s
Roughness coefficient = 0·03 10 marks
(c) The project of constructing a small road in a rural area consists of various activities as given in the table below. The time (in weeks) and cost (₹ in lakh) required for completion of each activity is also given.
| Activity | Normal Time (Weeks) | Normal Cost (₹ in lakh) |
|----------|---------------------|-------------------------|
| 1-3 | 9 | 90 |
| 1-2 | 12 | 180 |
| 2-3 | 18 | 210 |
| 3-4 | 20 | 360 |
The construction of road started from 1st January. The project was reviewed after 13 weeks and the following conditions were observed:
(i) Activities 1 – 2 and 1 – 3 are completed as originally planned.
(ii) Activity 2 – 3 is in process and will require 19 more weeks to complete.
(iii) Activity 3 – 4 has not started.
Based on the above review after 13 weeks, formulate a new project including all activities.
Will the project be completed by 15th August of the same year?
If the project is to be completed in 49 weeks, determine how much activity 3 – 4 is to be crashed and what will be the increase in project cost?
Assume crash cost for activity 3 – 4 is ₹ 450 lakh and crash time is 17 weeks. 15 marks
हिंदी में पढ़ें
(a) मैदानी भू-भाग में एक दो-लेन का राज्य महामार्ग, कटाई परिछेद में 2·0% कैम्बर के साथ एक 480 m त्रिज्या के वक्र को संचरित करता है । बाह्योथान को अभिकल्पित कीजिए तथा स्वच्छ रेखाचित्रों की सहायता से अभिकल्पित बाह्योथान को प्राप्त करने की प्रक्रिया की व्याख्या कीजिए । 15 अंक
(b) (i) एक डम्पी लेवल और 4·0 m स्टाफ की सहायता से निम्नलिखित क्रमिक पाठ्यांक एक सतत ढालु जमीन पर प्राप्त किए गए । यदि प्रथम बिंदु का समानित तल (आर.एल.) 99·000 m है, तो लेवल बुक में पाठ्यांकों की प्रविष्टि करते हुए अंतिम बिंदु के समानित तल की गणना कीजिए । सामान्य जाँचों का भी प्रयोग कीजिए । 10 अंक
3·815, 2·500, 1·335, 2·980 तथा 0·800 m
(ii) एक महामार्ग परिछेद के दोनों तरफ पार्श्व नालियों से निस्सारित किए जाने वाले पानी की अधिकतम मात्रा 1·8 m³/s है । निम्नलिखित परिस्थितियों के लिए आयताकार पार्श्व नालियों का अभिकल्पन कीजिए । दोनों नालियों का निस्सरण समान है ।
प्रवाह का अधिकतम अनुज्ञेय वेग = 0·8 m/s
रुक्षता गुणांक = 0·03 10 अंक
(c) ग्रामीण क्षेत्र में एक छोटी सड़क निर्माण की परियोजना के लिए विभिन्न क्रियाएं नीचे दी गई तालिका में दी गई हैं । प्रत्येक क्रिया को पूरा करने के लिए आवश्यक समय (सप्ताह में) तथा लागत (₹ लाख में) भी दी गई है ।
| क्रिया | सामान्य समय (सप्ताह) | सामान्य लागत (₹ लाख में) |
|--------|----------------------|---------------------------|
| 1-3 | 9 | 90 |
| 1-2 | 12 | 180 |
| 2-3 | 18 | 210 |
| 3-4 | 20 | 360 |
सड़क निर्माण 1 जनवरी से प्रारंभ हुआ । 13 सप्ताह बाद परियोजना की समीक्षा की गई तथा निम्नलिखित परिस्थितियाँ प्रेक्षित की गईं :
(i) क्रियाएं 1-2 तथा 1-3 पूर्ण हो गईं, जैसे मूल-रूप में आयोजित थीं ।
(ii) क्रिया 2-3 प्रक्रिया में है और पूर्ण होने के लिए 19 सप्ताह और आवश्यक हैं ।
(iii) क्रिया 3-4 प्रारंभ नहीं हुई है ।
13 सप्ताह के बाद उपर्युक्त समीक्षा के आधार पर, सभी क्रियाओं को शामिल करते हुए एक नई परियोजना बनाइए ।
क्या परियोजना उसी वर्ष के 15 अगस्त तक पूरी हो जाएगी ?
यदि परियोजना को 49 सप्ताह में पूरा करना है, तो निर्धारित कीजिए कि क्रिया 3-4 को कितना क्रैश किया जाना है तथा परियोजना लागत में कितनी वृद्धि होगी ?
क्रिया 3-4 के लिए क्रैश लागत ₹ 450 लाख तथा क्रैश समय 17 सप्ताह मान लीजिए । 15 अंक
Answer approach & key points
Design requires systematic problem-solving with calculations and sketches. Allocate ~30% time to part (a) superelevation design with rotation diagrams, ~35% to part (b) numerical problems (levelling and drain design), and ~35% to part (c) CPM crashing analysis. Begin with clear problem statements, show all formulae with IRC/IS codes, present stepwise calculations, and conclude with practical feasibility checks.
- Part (a): Calculate superelevation for R=480m using IRC formula e=V²/225R, check against maximum 7% and 10% limits, apply ruling speed of 80 kmph for State Highway, and explain rotation about centre-line with inner edge depressed and outer edge raised
- Part (a): Draw three neat sketches showing (i) normal camber section, (ii) transition start with outer edge raised, (iii) full superelevation with rotated section
- Part (b)(i): Enter readings in standard level book format with BS, IS, FS columns, calculate rises and falls, verify ΣBS-ΣFS=Last RL-First RL=ΣRise-ΣFall, determine final RL
- Part (b)(ii): Apply Manning's equation V=(1/n)R^(2/3)S^(1/2) for rectangular drain, assume b=2y or given proportions, calculate dimensions for Q=0.9 m³/s per drain, check velocity < 0.8 m/s
- Part (c): Draw original network, identify critical path 1-2-3-4 (50 weeks), formulate revised network after 13 weeks with remaining durations, calculate new completion date and compare with 15th August (32 weeks from 1st Jan)
- Part (c): Determine crash requirement for 49-week completion, calculate cost slope for activity 3-4, find crash weeks needed and additional cost
Q4 50M solve Railway engineering and building construction materials
(a) In a layout of B.G. Yard, an 8° curve branches off from a 4° main curve in an opposite direction. If speed is restricted to 28·90 km/hr and permissible value of cant deficiency is 7·61 cm, determine the speed restriction on the main line. 15 marks
(b) (i) Differentiate between overburnt and underburnt bricks. Why are these bricks not recommended for construction works? 5 marks
(ii) List the general factors governing the selection of stone for construction purposes. What considerations would guide in selecting stone for the following use:
(I) Face work of a building, and
(II) Buildings facing the sea? 10 marks
(c) (i) Sketch a cross-section of a masonry wall and show coping, cornice, lintel, jamb and parapet wall in the sketch. Also briefly explain the use of the above parts of a building. 10 marks
(ii) Explain the terms eaves, eaves board, common rafters and tie beam with the help of a sketch of cross-section of a slopy roof. Also explain the purpose of tie beam. 10 marks
हिंदी में पढ़ें
(a) एक बी.जी. यार्ड के अभिन्यास में, एक 8° वक्र एक 4° मुख्य वक्र से विपरीत दिशा में पथांतरित होता है । यदि गति 28·90 km/hr तक प्रतिबंधित है और कैंट न्यूनता का अनुज्ञेय मान 7·61 cm है, तो मुख्य लाइन पर गति प्रतिबंध निर्धारित कीजिए । 15 अंक
(b) (i) चटका ईंट तथा अधजली ईंट में विभेदीकरण कीजिए । निर्माण कार्यों के लिए इन ईंटों को क्यों अनुशंसित नहीं किया जाता है ? 5 अंक
(ii) निर्माण उद्देश्यों के लिए पत्थर के चयन को प्रभावित करने वाले सामान्य कारकों की सूची बनाइए । निम्नलिखित उपयोग के लिए पत्थर के चयन हेतु कौन-से विचार मार्गदर्शित करेंगे :
(I) एक भवन के अग्रभाग कार्य, तथा
(II) समुद्र के सम्मुख भवन ? 10 अंक
(c) (i) एक चिनाई की दीवार के अनुप्रस्थ-पारिच्छेद का रेखांकन कीजिए और उस रेखाचित्र में कोपिंग, कॉर्निस, लिंटेल, जैम्ब तथा पैरापेट भित्ति प्रदर्शित कीजिए । एक भवन के उपर्युक्त भागों के उपयोग की संक्षेप में व्याख्या भी कीजिए । 10 अंक
(ii) एक ढालू छत के अनुप्रस्थ-पारिच्छेद के रेखाचित्र की सहायता से ईव्स, ईव्स बोर्ड, कॉमन राफ्टर्स और बंधक धरन (टाई बीम) पदों की व्याख्या कीजिए । बंधक धरन के उद्देश्य की भी व्याख्या कीजिए । 10 अंक
Answer approach & key points
Begin with the numerical solution for part (a) applying cant deficiency principles for reverse curves, allocating approximately 30% time due to its 15 marks weightage. Follow with descriptive responses for parts (b) and (c), spending roughly 35% on building materials (brick and stone selection) and 35% on architectural elements with sketches, ensuring all five sub-parts are addressed with appropriate depth proportional to their marks.
- Part (a): Application of cant deficiency formula for reverse curves with 8° branch and 4° main curve, calculating permissible speed on main line using D = 0.073 × V²/R relationship
- Part (b)(i): Clear distinction between overburnt (vitrified, distorted, black core) and underburnt (soft, porous, light color) bricks with reasons for rejection in construction
- Part (b)(ii): General factors for stone selection (strength, durability, appearance, workability, cost) plus specific considerations for face work (color, texture, uniformity) and marine environment (salt resistance, weathering)
- Part (c)(i): Accurate cross-section sketch of masonry wall showing coping, cornice, lintel, jamb and parapet with functional explanations for weather protection and structural support
- Part (c)(ii): Cross-section sketch of sloped roof depicting eaves, eaves board, common rafters and tie beam with explanation of tie beam's role in preventing roof spread