II

Professional Activities

1. Perform the Measurement of Horizontal Distances

• How it's done: Measured using chains, tapes, or EDM (Electronic Distance Measurement) tools via total stations or GPS systems.
  
  

• Considerations:
  
  

  • Slope correction if not measuring horizontally.
    
    

  • Temperature correction for tapes.
    
    

  • Tension and sag corrections (especially with steel tapes). Sag Correction= w^2 *  L  /  24 P^2
    
    

• References:
  
  

  • Lindeburg (CERM)
    
    

  • Cuomo
    
    

  • Wolf & Brinker
    
    

  • Ghilani
    
    

2. Perform the Measurement of Angles

• Instruments used: Theodolite or total station.
  
  

• Types of angles:
  
  

  • Horizontal angle: Often used in traverses and layout.
    
    

  • Vertical angle: Used in determining elevation changes (trigonometric leveling).
    
    

• Procedure:
  
  

  • Sight two known points.
    
    

  • Record angle from instrument zero or a reference.
    
    

• References:
  
  

  • Anderson & Mikhail
    
    

  • Wolf & Brinker
    
    

  • CERM
    
    

3. Perform the Measurement of Elevations

• Two main methods:
  
  

  • Differential leveling: Uses a level and rod to measure elevation difference between points.
    
    

  • Trigonometric leveling: Uses angles and horizontal distances to calculate elevation changes.
    
    

• Key Concepts:
  
  

  • Height of Instrument (HI)
    
    

  • Back sight (BS), Fore sight (FS)
    
    

  • Elevation = HI - FS (or HI + BS if leveling up)
    
    

• References:
  
  

  • Ghilani
    
    

  • Moffitt & Bossler
    
    

  • Cuomo
    
    

  • CERM
    
    

4. Determine Potential Construction Conflicts

• Purpose: Identify where new structures might interfere with:
  
  

  • Existing utilities
    
    

  • Substructures (e.g., foundations, tunnels)
    
    

  • Right-of-way or property boundaries
    
    

• How:
  
  

  • Overlay proposed design on existing topographic survey.
    
    

  • Use GIS or field verification tools.
    
    

• References:
  
  

  • Subdivision Map Act
    
    

  • CERM
    
    

  • Surveying with Construction Applications (Kavanagh)
    
    

Topics May Include

1. Establishing Points or Alignments Using Distances and Angles

• Use: For roadway centerlines, property lines, or building layout.
  
  

• Method:
  
  

  • Set instrument over known point.
    
    

  • Measure angle and distance to new point.
    
    

• Terms:
  
  

  • Traverse, Backsight, Foresight
    
    

  • Bearing/Azimuth systems
    
    

• References:
  
  

  • Cuomo
    
    

  • Wolf & Brinker
    
    

  • Anderson & Mikhail
    
    

2. Establishing Elevations Using Trigonometric and Differential Leveling

• Trigonometric Leveling:
  
  

  • Used where differential leveling is impractical (e.g., across rivers, valleys).
    
    

  • Requires vertical angle and horizontal distance.
    
    

• Differential Leveling:
  
  

  • Preferred for high-accuracy.
    
    

  • Setup level at midpoint between two points to reduce error.
    
    

• References:
  
  

  • Ghilani
    
    

  • Moffitt & Bossler
    
    

  • Cuomo
    
    

  • CERM
    
    

3. Surveying Equipment Usage

• Common Equipment:
  
  

  • Total station: Combines EDM and theodolite.
    
    

  • Auto-level or digital level: For differential leveling.
    
    

  • Leveling rod, tripod, prism pole, GPS rover.
    
    

• Skills:
  
  

  • Set up, calibrate, and troubleshoot instruments.
    
    

  • Check for collimation and parallax errors.
    
    

• References:
  
  

  • Anderson & Mikhail
    
    

  • Ghilani
    
    

  • Kavanagh & Slattery
    
    

4. Creating and Checking Level Notes

• Field Book Entries:
  
  

  • Date, weather, crew, project
    
    

  • Station, BS, FS, HI, Elevation
    
    

  • Loop closure check to detect errors
    
    

• Types of Level Notes:
  
  

  • Height of instrument method
    
    

  • Rise and fall method
    
    

• Importance:
  
  

  • Legal documentation of field work.
    
    

  • Must be neat, error-checked, and signed.
    
    

• References:
  
  

  • Cuomo
    
    

  • CERM
    
    

  • Wolf & Brinker
    
    

3 Definitions

🔹 Interior Angle

The angle measured inside a traverse polygon at a vertex between two adjacent lines.

🔹 Deflection Angle

The angle by which a line deflects from the extension of the previous line, measured from the back line to the forward line (right or left).

🔹 Bearing Change

The change in direction (azimuth or bearing) from one line to another.

Key Formulas

1. Deflection angle is related to interior angle by:
   δ=180∘−θ\delta = 180^\circ - \thetaδ=180∘−θ
   where:
   
   

   • δ\deltaδ = deflection angle
     
     

   • θ\thetaθ = interior angle
     
     

2. Bearing change between two lines is equal to the deflection angle if turning from the extension of one line to the next.
   
   

Example Breakdown

Given:

• Interior angle = 65°
  
  

• Using the formula:
  δ=180∘−65∘=115∘\delta = 180^\circ - 65^\circ = 115^\circδ=180∘−65∘=115∘

• Therefore, the bearing change (change in direction from one leg to the next) is 115°
  
  

But the original question says:

Interior angle = 65°, deflection = 115°, what is the bearing change?

This phrasing is confusing because:

• If deflection angle is 115°, it already is the bearing change (it's the angle turned between two lines).
  
  

• There's no additional calculation needed. So bearing change = 115°
  
  

❌ Why “180 - 115 = 65°” is incorrect in this context:

That reverses the formula. The deflection is derived from the interior angle, not the other way around.

✅ Corrected Answer

If interior angle is 65°, then deflection = 115°, and the bearing change is also 115°.

📚 References:

• Ghilani, Elementary Surveying (15th Ed.), Chapter on traverse adjustment and angle types.
  
  

• Anderson & Mikhail, Surveying: Theory and Practice, angle relationships and traverse geometry.
  
  

• Cuomo, Surveying Principles, definitions of angle types and layout procedures.
  
  

Would you like me to revise the quiz code to reflect this correction too?

You said:

farsi

ChatGPT said:

حتماً، در ادامه توضیح فارسی این مسئله را می‌بینید:

🔷 تعریف‌ها

زاویه داخلی (Interior Angle):
زاویه‌ای است که بین دو خط مجاور در یک چندضلعی (مانند تراورس) در داخل شکل اندازه‌گیری می‌شود.

زاویه انحراف (Deflection Angle):
زاویه‌ای است که جهت یک خط نسبت به امتداد خط قبلی تغییر می‌کند. این زاویه بین امتداد خط قبلی و خط بعدی محاسبه می‌شود (به سمت راست یا چپ).

تغییر برد (Bearing Change):
میزان تغییر جهت از یک خط به خط بعدی در یک مسیر.

🔸 فرمول رابطه زاویه داخلی و زاویه انحراف:

زاویه انحراف=180∘−زاویه داخلی\text{زاویه انحراف} = 180^\circ - \text{زاویه داخلی}زاویه انحراف=180∘−زاویه داخلی

✅ مثال:

فرض کنید زاویه داخلی برابر با ۶۵ درجه است.

محاسبه زاویه انحراف:

زاویه انحراف=180∘−65∘=115∘\text{زاویه انحراف} = 180^\circ - 65^\circ = 115^\circزاویه انحراف=180∘−65∘=115∘

پس اگر زاویه داخلی داده شده باشد، زاویه انحراف برابر ۱۱۵ درجه می‌شود.

در سؤال شما آمده:
زاویه داخلی = ۶۵° و زاویه انحراف = ۱۱۵°
در نتیجه:
تغییر برد هم برابر است با همان زاویه انحراف = ۱۱۵ درجه

❗ توضیح مهم:

اگر در سؤال نوشته شده بود:

زاویه انحراف ۱۱۵ درجه است، برد جدید نسبت به قبلی چقدر تغییر کرده؟

جواب مستقیم است: همان ۱۱۵ درجه

ولی اگر زاویه داخلی داده شده باشد، باید از فرمول بالا برای محاسبه زاویه انحراف استفاده کرد.

📘 منابع:

• کتاب Ghilani، برداشت مقدماتی، چاپ ۱۵
  
  

• کتاب Anderson & Mikhail، تئوری و عمل نقشه‌برداری
  
  

• کتاب Cuomo، اصول نقشه‌برداری
  
  

اگر مایل باشی، سوال مربوطه را در آزمون HTML هم اصلاح می‌کنم. می‌خواهی این رو هم درست کنم؟