Civil Engineering
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*ለሲቪል ; ለአርክቴክቶች÷ለኮንስትራክሽን ÷ ለሀይድሮሊክ መሀንዲሶች እና ተማሪዎች የተዘጋጀ ትምህርታዊ ቻናል ፡፡

@engineer03


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ASTU research guide.docx
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ለሪሰርች አጋዠ ይሆናችኋል
✳️Types of Formwork
▶️Foundation Formwork. Foundation formworks can be designed in various ways. ...
▶️Wall Formwork. Wall formwork consists of vertically arranged upright timbers (formwork bearers) to which sheeting boards are nailed at the concrete side. ...
*Ceiling Formwork. ...
*Beam Formwork. ...
*Column Formwork.
✅Formwork functions
The formwork is the main means of work in the moulding process of the concrete. Basically the process of formwork making has to meet the following requirements: - The structural component to be produced is to be moulded with the projected dimensions keeping the admissible tolerances.
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⚡http://t.me/engineer03
Civil engineering huge machinery 👇👇👇👇👇👇👇👇👇👇👇👇
👆👆👆👆Civil engineering huge machinery 👆👆👆👆
👉FACTORS AFFECTING CONCRETE STRENGTH
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▶️Concrete strength is effected by many factors, such as quality of raw materials, water/cement ratio, coarse/fine aggregate ratio, age of concrete, compaction of concrete,
temperature, relative humidity and curing of concrete.
1. Quality of Raw Materials:
*Cement: Provided the cement conforms with the appropriate standard and it has been stored correctly (i.e. in dry conditions), it should be suitable for use in concrete.
*Aggregates: Quality of aggregates, its size, shape, texture,
strength etc determines the strength of concrete. The
presence of salts (chlorides and sulphates), silt and clay also
reduces the strength of concrete.
*Water: frequently the quality of the water is covered by a
clause stating “..the water should be fit for drinking..”. This
criterion though is not absolute and reference should be
made to respective codes for testing of water construction
purpose.
2. Water / Cement Ratio:
The relation between water cement ratio and strength of
concrete is shown in the plot as shown below:
The higher the water/cement ratio, the greater the initial spacing between the cement grains and the greater the
volume of residual voids not filled by hydration products.
There is one thing missing on the graph. For a given cement
content, the workability of the concrete is reduced if the
water/cement ratio is reduced. A lower water cement ratio
means less water, or more cement and lower workability.
However if the workability becomes too low the concrete
becomes difficult to compact and the strength reduces. For a
given set of materials and environment conditions, the
strength at any age depends only on the water-cement ratio,
providing full compaction can be achieved.
3. Coarse / fine aggregate ratio:
Following points should be noted for coarse/fine aggregate
ratio: If the proportion of fines is increased in relation to
the coarse aggregate, the overall aggregate surface
area will increase.
If the surface area of the aggregate has increased, the water demand will also increase.
*Assuming the water demand has increased, the
water cement ratio will increase Since the water cement ratio has increased, the compressive strength will decrease.
4. Aggregate / Cement Ratio:
*Following points must be noted for aggregate cement ratio:
If the volume remains the same and the proportion of cement in relation to that of sand is increased the surface area of the solid will increase.
*If the surface area of the solids has increased, the
water demand will stay the same for the constant
workability.
*Assuming an increase in cement content for no
increase in water demand, the water cement ratio will
decrease.
*If the water cement ratio reduces, the strength of
the concrete will increase.
*The influence of cement content on workability and strength
is an important one to remember and can be summarized as
follows:
1. For a given workability an increase in the proportion of
cement in a mix has little effect on the water demand and results in a reduction in the water/cement ratio.
2. The reduction in water/cement ratio leads to an increase
in strength of concrete.
3. Therefore, for a given workability an increase in the
cement content results in an increase in strength of concrete.
5. Age of concrete: The degree of hydration is synonymous with the age of concrete provided the concrete has not been allowed to dry out or the temperature is too low.
*In theory, provided the concrete is not allowed to dry out,
then it wil always be increasing albeit at an ever reducing
rate. For convenience and for most practical applications, it
is generally accepted that the majority of the strength has been achieved by 28 days.
6. Compaction of concrete: Any entrapped air resulting from inadequate compaction of the plastic concrete will lead to a reduction in strength.
If there was 10% trapped air in the concrete, the strength will fall down in the range of 30 to 40%. CONT'D 👇👇👇
7. Temperature: The rate of hydration reaction is temperature dependent.
*If the temperature increases the reaction also increases. This
means that the concrete kept at hi gher temperature will gain
strength more quickly than a similar concrete kept at a lower
temperature. However, the final strength of the concrete kept at the higher temperature will be lower. This is because the physical form of the hardened cement paste is less well structured and more porous when hydration proceeds at faster rate.
*This is an important point to remember because temperature
has a similar but more pronounced detrimental effect on
permeability of the concrete.
8. Relative humidity: If the concrete is allowed to dry out, the hydration reaction will stop.
*The hydration reaction cannot proceed without
moisture. The three curves shows the strength development
of similar concretes exposed to different conditions.
9. Curing: It should be clear from what has been said above that the detrimental effects of storage of concrete in a dry
environment can be reduced if the concrete is adequately
cured to prevent excessive moisture loss.

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👉ሸገር አዱ ገነት❤️
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🙏ወብ ምሽት ተመኘን😍
👉በኮንስትራክሽን ውል የግንባታ መዘግየት ቅጣት/Liquidated damage/
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▶️በጉባዔ አሰፋ(ጠበቃና የህግ አማካሪ)
====================
*በኮንስትራክሽን ውል ላይ የውሉ የግንባታ ስራ ተብሎ የተቀመጠውን በዲዛይኑ እና ዝርዝር ስፔስፊኬሽኑ መሰረት በውሉ በተቀመጠው የጊዜ ገደብ ሰርቶ ማጠናቀቅ የተቋራጩ ሀላፊነት ነው፡፡
*ተቋራጩ የውሉን የግናባታ ስራ በውሉ በተቀመጠው የጊዜ ገደብ በወቅቱ ሰርቶ ያላጠናቀቀ እንደሆነ ከውሉ ማጠናቀቂያ ጊዜ/completion date/ በኋላ ግንባታው እስከሚጠናቀቅበት ጊዜ ድረስ ለእያንዳንዱ ቀን ተቋራጩ የግንባታ መዘግየት ቅጣት/Liquidated damage/ የመክፈል ሀላፊነት ይኖርበታል፡፡
*በውሉ በተቀመጠው የጊዜ ገደብ ሲባል ምን ማለት ነው? አንዳንድ አሰሪዎች/client/ በግንዛቤ እጥረት በውሉ ላይ የተቀመጠው ተቋራጩና አሰሪው ለግናባታው ማጠናቀቂያ የተስማሙበትን የቀን ብዛት/የጊዜ እርዝማኔ/ መቆጠር የሚጀምረው ውሉ በግራ ቀኙ ከተፈረመበት ቀን ጀምሮ እንደሆነ ይረዱታል፡፡ይሄ አረዳድ ስህተት ነው፡፡
*በኮንስትራክሽን ውል ስለ ጊዜ አቆጣጠር በተለይ የግንባታ ውል የተደረገበት ቀን/contract signing date/ ፣ሞቢላይዜሽን ፔሬድ/mobilization period/፣የሳይት ርክክብ/site handover/፣ የስራ መጀመሪያ ቀን/commencement date/ እና የስራ ማጠናቀቂያ ቀን/completion date/ የሚሉትን መረዳት የግንባታ መዘግየት ቅጣት/Liquidated damage/ የሚለውን በአግባቡ ለማወቅ ይጠቅማል፡፡
*በመሰረቱ በውሉ የተቀመጠው የስራ ማከናወኛ የጊዜ ገደብ መቆጠር የሚጀምረው ተቋራጩ የግናባታውን ሳይት ከአሰሪው ከተረከበ በኋላ ነው፡፡ይሄውም ከሳይት ርክክብ በኋላ የስራ መጀመሪያ ቀን /commencement date/ በመሀንዲሱ የሚወሰን እና ለተቋራጩ የሚገለጽለት ይሆናል፡፡
*እንግዲህ ከዚሁ በመሀንዲሱ ከሚወሰነው የስራ መጀመሪያ ቀን ጀምሮ በውሉ ላይ የተቀመጠው ቀን ይቆጠርና የስራ ማጠናቀቂያ ቀን/completion date/ መቸ እንደሆነ ለማወቅ ያስችላል ማለት ነው፡፡
*እዚህ ላይ ሊታወቅ የሚገባው ነገር በኮንስትራክሽን ውሉ ላይ የተወሰነውን የስራ ክፍል ከውሉ የማጠናቀቂያ ጊዜ አስቀድሞ ለማጠናቀቅ ውል ሊደረግ የሚችልበት እድልም አለ፡፡/part work completion/ ማለት ነው፡፡የቀን አቆጣጠሩ ከላይ እንደተብራራው የሚሰላ ይሆናል፡፡
*ስለሆነም የግንባታ መዘግየት ቅጣት የሚለው ጉዳይ የሚመጣው ተቋራጩ የውሉን የግንባታ ስራ በውሉ ስራ የማጠናቀቂያ ጊዜ /completion date/ ሳያጠናቅቅ የቀረ እንደሆነ ነው፡፡የገንዘብ ቅጣቱ የሚጣለው በተቋራጩ ላይ ነው፡፡ተቋራጩ ግንባታውን ላዘገየበት ለእያንዳንዱ ቀን በውሉ የተቀመጠውን የግንባታ መዘግየት ቅጣት የሚከፍል ይሆናል፡፡በነገራችን ላይ እየተቀጡ መስራት ለተቋራጩ መብትም ጭምር ነው፡፡ይህ ማለት አሰሪው የውሉ ማጠናቀቂያ ጊዜ ስላለቀ ውል አቋርጣለሁ ማለት አይችልም፡፡በውሉ ላይ የተቀመጠው የመዘግየት ቅጣት ጣሪያ መጠን ከሞላ በኋላ ግን አሰሪው ውል ማቋረጥ ይችላል፡፡ውል ከተቋረጠ በኋላ የመዘግየት ቅጣት የሚባል ነገርም የለም፡፡
*ሌላው ተቋራጩ ወደ መዘግየት ቅጣት እንዲገባ ከመደረጉ አስቀድሞ በአግባቡ መረጋገጥ ያለበት ነገር መሀንዲሱ ለተቋራጩ የጊዜ ማራዘሚያ/time extension/ ፈቅዷል ወይስ አልፈቀደም የሚለው ነጥብ ነው፡፡ምክንያቱም ለተቋራጩ የጊዜ ማራዘሚያ ተፈቅዶለት ከሆነ የግንባታ ማጠናቀቂያ ጊዜውም አብሮ ስለሚራዘምና ቀኑ ስለሚቀየር ነው፡፡
*የሀገራችንን የህግ ማእቀፍ በዚህ ረገድ ምን ይላል? የሚለውን ለመመለስ በፍትሀብሄር ህግ አንቀጽ 1887 እስከ 1895 ድረስ የተደነገጉትን መዳሰስ ይጠይቃል፡፡
*በፍትሀብሄር ህግ አንቀጽ 1889 ላይ ተዋዋዮች በውላቸው ምናልባት አንደኛው ወገን እንደውሉ ግዴታውን ያልፈጸመ እንደሆነ ወይም አጓድሎ የፈጸመ እንደሆነ ወይም አዘግይቶ የፈጸመ እንደሆነ የሚከፍለውን የመቀጮ መጠን አስቀድመው በውላቸው ለመወሰን እንደሚችሉ በሚፈቅድ መልኩ ተደንግጓል፡፡እዚህ ላይ የውል ግዴታን አዘግይቶ መፈጸም ስለሚያስከትለው ቅጣት የሚዋዋሉት በተለይ የግንባታ መዘግየት ቅጣት/liquidated damage/ የሚመለከት ይሆናል፡፡
*የመዘግየት ቅጣት ስምምነት ባለ ጊዜ አሰሪው የውሉ ስራ እንዲፈጸምና የቅጣት ገንዘቡንም ለመቀበል መብት እንደሚኖረው የፍ/ህ/ቁ 1890(2) ይደነግጋል፡፡እንደዚሁም አሰሪው ኪሳራ ባይደርስበት እንኳ የመዘግየት ቅጣት ገንዘቡ ሊከፈለው እንደሚገባ የፍ/ህ/ቁ 1892(1) ይደነግጋል፡፡እንግዲህ ተቋራጩ ግንባታውን በወቅቱ ያላጠናቀቀው አሰሪውን ሆነ ብሎ ለመጉዳት አስቦ ጉልህ በሆነ ቸልተኝነት ወይም በከባድ ጥፋት መሆኑ የተረጋገጠ እንደሆነ አሰሪው በውሉ ከተቀመጠው የቅጣት ገንዘብ በላይ በደረሰበት ትክክለኛ ጉዳት መጠን ልክ ከተቋራጩ ላይ ኪሳራ ለመጠየቅ እንደሚችል የፍ/ህ/ቁ 1892(2) ይደነግጋል፡፡
*ሌላው የመዘግየት ቅጣት መጠን በዳኞች ሊቀነስ የሚችልበት እድል ስለመኖሩ የፍ/ህ/ቁ 1893 ይደነግጋል፡፡ይሄውም ተቋራጩ ግዴታውን በከፊል የፈጸመ ሆኖ ሲገኝ ነው፡፡ይህ ማለት ተቋራጩ ባከናወነው ስራ ሁሉ ቅጣት የሚጣልበት አይሆንም ማለት ነው፡፡
*በዚህ ረገድ በሲቪል ግንባታ ስራዎች ቋሚ የውል መተዳደሪያ አንቀጽ 47(1) ላይ ተቋራጩ ስራውን በውሉ የማጠናቀቂያ ጊዜ ካላጠናቀቀ ለዘገየበት ለእያንዳንዱ ቀን የውሉን ዋጋ 1/1000 እንደሚከፍል እና ይሄውም አጠቃላይ መጠኑ ከውሉ ዋጋ ከ20% መብለጥ እንደማይችል ይደነግጋል፡፡ሆኖም ግን በከፊል ለተከናወነው ስራ መሀንዲሱ ማረጋገጫ ሰርተፍኬት በሰጠ ጊዜ የቅጣቱ መጠን የሚሰላው ባልተከናወነው ስራ መጠን ዋጋ ላይ በመመስረት ይሆናል ማለት ነው፡፡
*በመጨረሻም የመዘግየት ቅጣት በኛ ሀገር ከላይ እንዳየነው እንደቅጣት የሚቆጠርና በህጉ ቅጣቱ እውቅና የሚሰጠው ሲሆን በኮመን ሎው የህግ ስርአት ግን ቅጣት አይደለም፡፡በኮመን ሎው ሊኩዴትድ ዳሜጅ በአሰሪው ላይ ከደረሰው ጉዳት ጋር እኩል ሆኖ መመዛዘን የሚኖርበት ሲሆን የቅጣት አይነት ተመሳሳይ ባህሪ ካለው ተፈጻሚነት አይኖረውም፡፡ አመሰግናለሁ!

http://t.me/engineer03
👉አሁን እስቲ ስለ Pile foundation ትንሽ እንበል...
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▶️Pile foundations are the part of a structure used to carry and transfer the load of the structure to the bearing ground located at some depth below ground surface.
*The main components of the foundation are the pile cap and the piles.
*Piles are relatively long and slender members used to transmit foundation loads through soil strata of low bearing capacity to deeper soil or rock having a higher bearing capacity
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❇️The purpose of apile foundation
💠to transmit a foundation load to a solid ground
💠to resist vertical ,lateral and uplift load
💠to reduce excessive settlement
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✅ When pile foundation is used ??
➡️The soil near the surface does not have sufficient bearing capacity to support the structural loads
➡️The estimate settlement of the soil exceed tolerable limits
➡️Differential settlement due to soil variability is happen
➡️The structural loads consist of lateral loads ,moments & uplift force singly or in combination
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✳️pile capacity
🔴The ultimate bearing capacity of a pile is the maximum load which it can carry without failure or excessive settlement of the ground
🔴The allowable load on a pile is the load which can be imposed upon it with an adequate margin of safety ,it may be the ultimate load divided by a suitable factor of safety,or the load at which the settlement reaches the allowable value
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🅾The bearing capacity of apile depends on:-
👉The method of installation
👉pile c-xes such as pile length ,cross section ,and shape
👉soil configuration and short and long-term soil properties.
: http://t.me/engineer03
👉FOR MORE
Which one is correct ? Why? Use discussion group

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@engineersWorks
Busan South Korea 🇰🇷

ውብ ምሽት ተመኘን
Reinforced_concrete_design_to_eurocode_2_ed_2007.pdf
56.1 MB
👉Reinforced concrete design to eurocode 2
AASHTO LRFD Bridge Design Specifications 8th Ed. 2017.pdf
105.7 MB
👉For those of you who are taking Bridge design course! #Request
Columns are designed for minimum eccentricity

A. 10mm
B. 20mm
C. 40mm
D. All

Use discussion group and we justify the reason
👇🏼👇🏼👇🏼
@engineersWorks