Construction of Hill Roads

Construction of Hill Roads (Retaining Walls, Breast Walls and Parapets)

The retaining walls are the most important structure in a hill road construction to provide adequate stability to the road way , and to the slope.

Fig-01)Retaining walls

 The Retaining walls are usually constructed on the valley side of the road way and also on the cut hill side to prevent land slide towards the roadway. 

The thickness of the wall at the top is usually kept as 60 cm and at the bottom it may be kept according to the following thumb rule 

: For walls in height < 6 m, 

the retaining wall at the bottom (thickness) = 0.4 X height. 

For walls in height > 6 m ,

 the retaining wall at the bottom (thickness) = 0.4 x height +30 cm. 

A batter of 1 on 12 may be given to the wall on the outside, The breast walls are constructed on the hill side of the roadway to retain the earth from slippage.

Fig-02) Breast wall (During Construction)

 The wall may be kept 60 cm thick throughout and sloped along the natural slope of the earth, it has to protect.

Fig-03) Breast Wall 

 The parapet walls are usually required on the valley side of the roadway to guide the vehicles properly to the roadway.

Fig-04) Hill Road

 The thickness of the wall is uniform throughout and 60 cm. 

The height is usually kept as 75 cm above the berm level. May be kept as 75 cm above the berm level.    

Fig-05) Hill Road

Works on footpaths alternative way for pedestrians

Works on footpaths alternative way for pedestrians

 an alternative safe route for pedestrians must be provided, if it is necessary closed footway or part of foot way.

 Temporary pedestrian way should never be less than 1 meters wide and whenever possible, they should be 1.5meters or more in width. 

Pedestrian Safety 

it should be ensured there is no danger to pedestrians from falling object or sharp edges, and they will not fall over or bump into anything. Scaffolding can be marked with white bands at eye level and allow at least 2.10 meters headroom. 

Kerb ramps or raised footways should be provided to help blind, poorly sighted, elderly and disabled people , and for those with prams or wheel chairs. 

Pedestrian Barriers

 it should be used to mark out any temporary foot way barrier must always be used to protect pedestrian from traffic, excavations, plan or materials. Place road danger lamps at the end of the barriers at night. Potable pedestrian barriers which may include mesh, should be reasonably riding. 

(a) A hand rail fixed at between 1 meters and 1.2 meters above ground level, which should be reasonably smooth and rigid for pedestrians at hold to obtain guidance and some measure of support. 

(b) A visibility panel at least 150 mm deep which may be integral with handrail or separator must be fixed s that its upper edge is minimum of 0.90 meters above ground level. 

(c) Visibility panels of yellow, white , or orange colors are best for detection by partially slighted people, while the red and white rail give a good contrast and provides inter changeability with traffic barriers 

Deep Excavations

 if excavations are deeper than 1.20 meters , stronger barriers will be required.  

Precautionary measures/safety measures for specific activity

 Precautionary measures/safety measures for specific activity 

the general precautionary measures have been specified , it is considering imperative to highlight the precautionary measure in different activities.

 (a) Formation cutting works

 (i) during formation cutting, separate sentries are to be positioned during blasting with red flag to stop and regulate traffic during blasting.

 (ii) when dower is working above the road level, sentries to be positioned to stop and regulate traffic keeping watch on the movement of dower 

(iii) sentry to be positioned to watch falling boulders , and earth from top and to warm the passer. (iv)Development of female laborers be avoided in formation cutting Works.

(b) Surfacing works 

(i) Haphazard stacking of stone boulder on the road may cause injury to passer-by due to such boulders getting deflected out by the tires of moving vehicles. 

(ii) Goggles and rubber flap to be invariably issued to laborers engaged in stone/ metal / stone breaking work. (iii) Hand gloves and gumboots should be issued to laborers engaged in resurfacing work. 

(iv) First aid box to be placed in position in all work sites. 

(v) No person should be allowed to travel on the body of water truck 

(vi) special training should be given to the laborers engaged in manual wetting static road roller wheels to prevent accident. 

 (C) Permanent Works

out) While carrying out excavation work, sufficient care to be taken avoid side collapse which may cause injury to laborers working inside. 

(ii) At excavation site, guard stones for guiding moving vehicles to be placed. (iii) Laborers working in the excavation pit should use helmet.

 (iv) Whenever excavation pit is adjoining to river/ nallah, proper watch man to be kept to give warning in case of flash flood during monsoons. 

(D) Snow clearance operations

 

(i) Proper winter clothing for the working group to be ensured. 

(ii) All vehicles plying in the area should use anti snow skid chain. 

(iii) Additional lighting arrangement to be provided for late work. 

(E) Road side Quarrying

 (i) Stone quarry should not be operated just above or below the main highway as far as possible. 

(ii) First aid box to be placed in position in all work sites. 

(iii) Warning sign boards to be placed at appropriate locations near quarry site.

 (iv) Laborers working in quarry to be used helmet. 

(F) River bed quarrying 

(i) Quarrying not to be allowed within a distance of 100 meters from any cross drainage structures (culvert, bridges , etc) since it may cause changes in the flow pattern stream. 

(ii) Quarrying within 50 m of any river training works be avoided.

 (iii) Laborer Camp  

What is different types of Traffic Control Devices?

Traffic Control Devices

these are the equipment and installations over and on the road which individually and collectively perform the following tasks.

(i) Warn the road user

(ii) Inform the road user

(iii) Guide the road user

(iv) Modify road user behaviour

(v) Protect the road user and the vehicle

(vi) Ensure safe passage to the road user

(vii) Provide a safe working area.

the primary traffic control devices used in working zones are signs, delineators,  pylons, pavement marking, barricades, cones and flashing lights.

The  following general rules should apply to all these devices.

(A) Comprehension:

it should be capable of being easily understood, must convey one and only one meaning, good and clean condition of the device aids comprehension.

(B) Visibility and stability :

it should be clearly visible both day and night properly aligned and legible at all times. these should not act as a rigid  obstacles in the event of a collision.

(C) Maintenance:

 It should be serviced and maintenance correctly.

Spare devices must be available during the entire period of construction.

(a) Clear visibility 

(b) Signs should be so placed that driver should have time for responses (c) it should be placed on left hand side of the road. Where special emphasis is required, duplicate signs should be installed at right side of roadway also. 

In hill roads, these are generally placed on the valley side of road unless road conditions warrant these to be placed on the hill side; and 

(d) The signs should be covered or removed when they are not required.  

Positioning of signs 

the outermost edge of sign adjoining  to shall not be less than 600 mm apart from the edge of the kerb on kerbed roads. 

On unkerbed roads, the extreme edge of the sign adjacent to the road shall be at a distance of two to three metre away from the edge of the carriageway depending on local situation but in no case, shall any part of sign come in the way of traffic.

Regulatory Sign

It imposes legal restrictions on all traffic.

It is essential that they are used only after consulting local police and traffic authorities. 

The most probably type of regulatory signs to be used in traffic control zones are Stop, Give Way, Do Not Enter, One Way, Straight Prohibited, Vehicles Prohibited in Both Directions, Left Turn Prohibited, Right Turn Prohibited, 'U' Turn Prohibited, Overtaking Prohibited, No Parking, No Stopping and No Standing, Keep Left, Compulsory Left Turn, Compulsory Right Turn, Compulsory Straight or Left Turn, Priority to vehicles in other direction, Priority to vehicles in this direction, Weight Limit, Axle Limit, Height Limit, Length Limit, Restriction Ends, Speed Limit Various other signs that are needed to regulate traffic may be required, which have not been standardized. 

They should conform to the general requirements of shape and colour and 

Warning Signs  

These are utilized in the traffic control zone to warn the drivers of specific hazards that may be encountered. Drivers should be alerted to potential hazards in sufficient time to adjust their movement and speed.

 The most common type of warning signs for the use in the traffic control zone are : Men At Work, Road Narrows (Single File Traffic), Right Lane Diverted, Left Lane Diverted, Right Lane Closed, Left Lane Closed, Median Closed, Diversion to other Carriageway, Traffic Signal Ahead Two Way Traffic, Rough Road, Slippery Road, Loose Chippings, Divided Road and Divided Road Ends.

What is temporary Diversions in Highway Construction?

Temporary Diversions
 Where the construction zone would near the road entirely, the remaining carriageway stretch would be inadequate for the traffic and create large retard and there is no appropriate  a replacement route, it will be mandatory to build a short-term carriageway for entirely or segment of the traffic. 

This is most common situation in the cases of any major repair or reconstruction of cross drainage works and failure due to, for example, floods. The temporary carriageway must satisfy the of pavement following requirements:-

fig.(i) Layout of signs and control devices for road closed with a diversion.

(i) It should have smooth horizontal and vertical profile with smooth vertical and horizontal curves.

  (ii) It should not get over-topped by flood or drainage discharges under any condition,

 (iii) It should have adequate capacity to cater to the expected traffic, 

(iv) It should be dust free and should ensure clear visibility at all times of day and night; and 

(v) Barricading should be provided to prevent construction material falling on the diversion.

(vi) Layout for sign and traffic control devices for temporary diversion.

आपूर्ति की दर में बदलाव का क्या आशय है?

आपूर्ति की दर में बदलाव का क्या आशय है? 

         आपूर्ति की दर में बदलाव 

(VARIATIONS IN RATE OF DEMAND)

आपूर्ति के अनुपात में भिन्नता शीर्ष की मांग की औसत दैनिक दर वर्ष के दिनों में आपूर्ति की जाने वाली पानी की कुल मात्रा का अनुपात है, जो वर्ष के दिनों से गुणा किया जाता है। 

 यदि प्रतिदिन अवलोकन की अवधि कम की जाती है, तो प्रति शीर्ष मांग की यह औसत दैनिक दर घटने की संभावना है। 

 इस प्रकार, यदि मांग की औसत दैनिक दर 100 है, तो: 

(i) मौसमी अधिकतम मांग (Seasonal maximum demand )130 हो सकती है;

 (ii) मासिक अधिकतम मांग (Seasonal maximum demand)

140 हो सकती है; और

 (iii) दैनिक अधिकतम मांग ,(Daily Maximum demand )180 या उससे अधिक हो सकती है। 

 ये भिन्नताएं कई कारकों के कारण होती हैं। जैसे लोगों की आदतें, जलवायु परिस्थितियां,  उद्योगों के प्रकार आदि।

 मौसमी, मासिक और दैनिक मांग (Seasonal, monthly and daily demand,) के लिए औसत से विचलन के लिए उपरोक्त आंकड़े केवल दृष्टांत के लिए लिए जाते हैं। 

 हर शहर में खुद की ख़ासियत होती है।

 और इसलिए, किसी विशेष निर्णय पर पहुंचने से पहले, विस्तृत अध्ययन आवश्यक हो जाता है। इसलिए हर मामले का अलग से अध्ययन किया जाता है। और मांग की औसत दर से भिन्नता के अनुसार काम किया जाता है।

 व्यवहार में, उपभोग की अधिकतम दैनिक दर (Maximum& Daily consumption )बहुत महत्वपूर्ण है। 

 यह अधिकतम दैनिक उपभोग 24 घंटे में किया जाना है। लेकिन 24 घंटे के दौरान मांग एक समान नहीं होगी।

और यह दिन के घंटे के अनुसार अलग-अलग होगी। माँगों की दर में प्रति घंटा भिन्नता दिखाने वाला एक विशिष्ट ग्राफ में दिखाया गया है।

 पानी की आपूर्ति की मांग सुबह और शाम को ज्यादा होती है।

 Slacks periods ,सुबह में और देर रात में होती है। 

 घंटे से घंटे तक पानी की मांग इस प्रकार परिवर्तनशील है। और अधिकतम प्रति घंटा की मांग औसत दैनिक मांग की तुलना में बहुत अधिक होगी। यह औसत दैनिक मांग का लगभग 150 प्रतिशत माना जा सकता है।

आइए हम मान लें कि औसत दैनिक मांग 240 लीटर पानी प्रति व्यक्ति है। 

 अधिकतम दिन में खपत की दर =(240 x 1.80) और

 उस दिन अधिकतम प्रति घंटा खपत की दर लगभग 

(10 × 1.80) X 1.50 

= 27 लीटर पानी प्रति व्यक्ति

 होगी।अधिकतम प्रति घंटा की मांग को पूरा करने के लिए, पंप या तो चर गति( Variable Speed) पर चलने के लिए या औसत गति( Average Speed) से चलाने के लिए हैं। पूर्व घटनाओं, में, प्रति घंटे की आवश्यकताओं के अनुसार पंपों की गति बदल दी जाती है। 

 पंपों को काम करने की इस विधि के परिणामस्वरूप बहुत असुविधा होती है।

  पंम्पों को इस तरह से औसत गति से चलाया जाता है। कि (Slack Demand) मांग अवधि में संग्रहीत अधिशेष पानी का उपयोग चरम मांग अवधि में किया जाता है। 

  पंम्पिग की औसत दर को बिंदीदार रेखा से दिखाया गया है। 

 बिंदीदार रेखा (Dotted line) के नीचे का क्षेत्र अधिशेष जल  (Surplus water ) को दर्शाता है।

और बिंदीदार रेखा (Dotted line) केके ऊपर का क्षेत्र जल की कमी को दर्शाता है।

 पंपिंग की औसत दर ऐसी होनी चाहिए।

 कि ये दोनों क्षेत्र लगभग बराबर हों। 

 इसका  यह है कि कम मांग अवधि के दौरान संग्रहीत अतिरिक्त पानी का उपयोग तीव्र आपूर्ति अवधि में किया जाना है। 

 अतिरिक्त पानी को इस उद्देश्य के लिए विशेष रूप से निर्मित टैंकों या जलाशयों में संग्रहित किया जाना है।

What is meant by variations in rate of Demand?

VARIATIONS IN RATE OF DEMAND The average daily rate of demand per head is the ratio of total quantity of water supplied during the year to the number of persons served multiplied by the days of year. 

This average daily rate of demand per head is likely to deviate, if period of observation is shortened.

 Thus, if average daily rate of demand is say 100, then: 

(i) seasonal maximum demand may be 130; monthly maximum demand may be 140; and daily maximum demand may be 180 or so. 

 (iii) These variations are due to the many factors such as habits of people, climatic conditions, types of industries, etc. 

The above figures for deviation from the average for seasonal, monthly , and daily demand, are taken for illustration only. 

separately and the variation from the average rate of demand is worked out accordingly. 

In practice, the maximum daily rate of consumption is very important. 

This maximum daily consumption is to be consumed in 24 hours.

 But demand during 24 hours will not be uniform , and it will vary according to hour of day. 

A typical graph showing the hourly variation in the rate of demands is shown in fig.

 The peak demands occur in the morning , and evening. 

The slack periods occur early in the morning , and late at night. 

The demand of water from hour to hour is thus variable and the maximum hourly demand will be much higher than the average daily demand. It may be assumed as about 150 percent of the average daily demand

 let us assume that the average daily rate of demand  240 litres of water per head. 

The rate of consumption on maximum day will about (240 x 1.80) and rate of maximum hourly consumption on that day will work out to be about 

(10 × 1.80) X 1.50 or 27 litres of water per head. 

In order to meet with the maximum hourly demand, the pumps are either to run at variable speeds or to run at an average speed. 

In the former case, the speeds of pumps are changed as per hourly requirements. 

This method of working the pumps results in great inconvenience. 

In the latter case, the pumps are run at an average speed in such a way that the surplus water stored at slack demand period is used at peak demand period. 

In fig. , the average rate of pumping is shown by a dotted line. 

The area below the dotted line shows surplus water and the area above the dotted line indicates the shortage of water. 

The average rate of pumping should be such that both these areas are nearly equal. 

This means that the excess water stored during slack demand period is to be consumed in peak demand period. 

The excess water is to be stored in tanks or reservoirs specially constructed for this purpose.