Wednesday, December 4, 2013

Super Typhoon Yolanda (Haiyan), Brought heartbreaking Devastation to Leyte and Samar, Visayas Region, Philippines

I will post soon the story of Super Typhoon Yolanda (Haiyan), which brought heartbreaking devastation to the Visayas Region in the Philippines...

Tuesday, October 22, 2013

7.2 Magnitude Earthquake and A Fall of Centuries Old Churches in the Philippines

A 7.2 magnitude earthquake with epicenter at Carmen, Bohol, Philippines has destroyed and devastated a total of 10 Heritage Churches, treasures of the Philippine history and culture. This historic churches had stood for over 300 years before quake. They include:

  • Baclayon Church, Bohol
  • Dauis Church, Bohol
  • Dimiao Church, Bohol
  • Loboc Church, Bohol
  • Loon Church, Bohol
  • Loay Church, Bohol
  • Maribojoc Church, Bohol
  • Basilica Minore del Sto. Nino, Cebu
  • Cebu Metropolitan Cathedral, Cebu
  • St. Catherine's Church, Carcar, Cebu

According to Atty. Trixie Angeles NCCA legal consultant.

"These are declared National Cultural Treasures which is the highest recognition a country can bestow on cultural properties."

The extent of the damage to the centuries-old churches in Bohol are very bad in the aftermath of the 7.2 Magnitude quake that struck the island of Bohol on Tuesday, October 15, 2013.

A certain Rodel has told the UN volunteer that his son, parents, sister and brother were buried alive, trapped inside their collapsed home for over six hours. He lost four of his family members.

Loboc Chuch
The Church of our Lady of the Immaculate Conception in Baclayon is considered to be one of the oldest churches in the Philippines. The Baclayon church is one of the best preserved Jesuit-built churches in the region. It was built in 1717 and completed in 1727. While Loboc church is the second oldest church in Bohol, according to an article in Bohol.ph.


Highways and Bridges
Aerial View at Sagbayan Town

Damage Highway/Road




Loon Bridge


Cortes Bridge

City and Municipal Halls

Sagbayan Municipal Hall


Monday, February 11, 2013

Banaue Rice Terraces, Stairway to Heaven-Philippines

This remarkable engineering works done by tribesmen of Ifugao province about 2,000 to 2,500 years ago carved from the hillsides. The tribes people done this with their bare hands, bare feet, stone chisels, wood tools, animal power. The rice terraces located approximately 1,500 meters (5000 ft.) above sea level and cover 10,000 plus square kilometers (about 4000 square miles) of mountainside, the terraces catches water from ancient irrigation system from the rain forest from above grounds.

The Banaue Rice Terraces started at the base of the mountain range and stretch on a thousand feet upward. If put end to end their total length would encircle half of the globe. Built approximately 2,000 years ago, the rice terraces manifest the engineering skill and ingenuity, diligence, perseverance of sturdy Ifugaos tribe people. Tribe people irrigated the terraces by means of mountain brooks, streams, springs connected and channeled into canals that run downward through hill to the terraces.



The Banaue Rice Terraces were declared a World Heritage Site by UNESCO only 17 years ago (1995) and is nearly part to the future of the tribes people.







Monday, January 7, 2013

The New 7 Wonders of Nature (Puerto Princesa Subterranean River National Park)

The Puerto Princesa Subterranean River National Park is located about 50 kilometers (30 miles) north of the city of Puerto Princesa, Palawan, Philippines. The national park is located at St. Paul mountain range on the northern coast of the island. In 2010, a group of geologist and environmentalist discovered that the underground river has a second floor, which means that there are small waterfalls inside the cave, there is also a huge cave dome, measuring 300 meters above the underground river, incredible rock formations, large bats, a deep water hole in the river, more river channels, marine creatures. Deeper areas of the underground river are impossible to explore due to lack of oxygen. On January 28, 2012, Puerto Princesa underground river was chosen as one of the New7Wonders of Nature. pls. link to this web address.

New7Wonders of Nature Underground River

Underground River in Palawan

Stalactites at the Subterranean River

Sunday, December 2, 2012

Secret of the Pyramids

Uploaded by swiit on July 22, 2007

For 4,500 years, this magnificent structure has been the subject of studies by engineers, architects, and archaeologist.






The Great Pyramid

Posted by Biblestudents on November 17, 2006

The mystery of the Great Pyramid the magnificent structure in the ancient world and one of the 7 wonders in ancient times.















Friday, November 16, 2012

Secrets of the Parthenon

Post from NOVA PBS on March 17, 2009

For 2,500 years, the Parthenon has been set on fire, devastated by earthquakes, looted for it's magnificent sculptures, disfigured by natures and defaced by inadequate skills in the restoration of this historic structures.. Presently, a team of engineers and architects is investigating the secrets and mysteries of this landmark of western civilization. The QUESTION is how did the Greeks designed and built this masterpiece?

Saturday, July 14, 2012

Reinforced Concrete Design

What makes Unique of RC...?

It is a COMPOSITE MATERIAL...
  • It requires APPLICATION of more involved Principles of Mechanics...
  • Structural Design is iterative requiring both ANALYSIS and DESIGN DECISIONS aided by judgment and EXPERIENCE.
  • ACI 318 -the model code in the United States of America for guiding the design of RC members, look at Chapter 8.
  • NSCP Code -the code in the Philippines..conforms to the provisions of ACI 318 Code!!!
Important Material Properties...

Concrete Strength and Steel Strength...
  • 28-day Compressive Strength, f'c: ACI 318 Code 2011 edition, Chapter 5.
  • Modulus of Elasticity of Concrete, Ec: ACI 318 Code 2011 edition, Chapter 8.5
  • Strength property or yield strength, fy..
  • Modulus of Elasticity of Steel, Es: 29,000,000 psi --ACI 318 Code 2011 edition.

1. --Procedures on how to Design Reinforced Concrete Beams!!!

Concrete Beam Sizing..!



Determination of Beam Size (b x h)---USE Spreadsheet or Hand Calculation!!!

Concrete Beam Size (b x h) or (b x d), FORMULA:

Formula for Beam Sizing
Beam Section, Strain and Force Diagram

Equilibrium Equation or Neutral Axis Distance, c -- Quadratic for c

Rebars Determination..

Area of Steel (As) determination!!!

Strength Formula and Area of Steel (As)
Area Steel (As) Formula
rho formula

The ACI Code 10.3.3 to 10.3.5 limits on the Steel Ratio (rho):

rho maximum
rho balance
1.1 Minimum Beam Size for which Deflections are NOT LIKELY to be a Problem.
1.1.1 Set Neutral Axis distance, c =< 0.375cb....

FORMULA for Beams Size NOT LIKELY to HAVE DEFLECTION PROBLEMS


1.2 Arrangement of Rebars, Splicing points and splice length, development length, hooks requirement, and required Stirrups.

Design of Stirrups and Spacing
Stirrups Spacing Requirements per ACI Code

Structural Integrity Requirements for Perimeter Beam

Structural Integrity requirements for Interior Beams

ACI Standard Bar Details

2. --Procedures on how to Design Reinforced Concrete Columns!!!

Lateral Tie Design

ACI Standard Bar Detailing for Columns
ACI Columns Rebars splicing details

ACI Standard Bar Bending Diagram

Minimum Column Steel and Ties requirements
2.A.--Structural design for Column using Interaction Diagram.

Column Interaction Diagram
2.B.--Example of ACI Interaction Diagram.
Interaction Diagram-Rectangular Section-Courtesy of ACI
Interaction Diagram-Spiral/Circular Section-Courtesy of ACI
2.C.--Summary of Column detail Requirements.

Column Design Requirement

2.1 Strength Reduction Factor, phi =0.70 -applicable up through ACI 318-1999; they have been changed to phi =0.65, for compression members (columns and beams under compression controls) beginning with ACI 318-2002 Code, and continuing with the ACI 318-05 and 2008 up to present.

3.--Example: Design of Column using MS Spreadsheet.

Design of Column MS Spreadsheet page #1

Design of Column MS Spreadsheet page #2

Rectangular Beam Design Example:

Data:
  1. Load and Span
  2. Material Properties -f'c, fy
material strength
Simple Beam with uniform load and point load
Calculation #1
Calculation #2
Calculation #3
Calculation #4

Hence, in more than 20 years of my practice, reinforced concrete design needs an in depth STUDY, and RESEARCH; therefore, for the information of the DRAFTSMAN drawing and/or drafting ("pag GUHIT" in local dialect) a proposed project and then observing a design drawings are not enough to say that you will know every aspects of concrete design. Concrete Design and Analysis are more on CALCULATIONS and application of more PRINCIPLES of MECHANICS.

References:
  1. Reinforced Concrete Design by Chu-Kia Wang and C. G. Salmon, 6th edition-1998;
  2. Building Code Requirements for Structural Concrete, ACI 318-2011, American Concrete Institute;
  3. Building Code Requirements for Structural Concrete, ACI 318-1963, 1971, 1977, 1995, 2002; 2005, 2008, 2011 editions;
  4. NSCP Code, volume 1-Buildings and volume 2-Bridges, 5th edition-2001, 6th edition-2010, Association of Structural Engineers of the Philippines;
  5. ACI Design Handbook -ACI 318-2004;
  6. ACI Detailing Manual 2004;
  7. ACI Manual for Concrete Practice 2005 and 2008;
  8. CRSI DESIGN HANDBOOK, 10th edition, 2008;
  9. Design of Concrete Structures by Arthur H. Nilson, 12th edition -1997, 13th edition, 14th edition-2008;
  10. Design of Reinforced Concrete by Jack C. McCormac, 3rd edition,-1993, 5th edition 2005; 7th edition;
  11. Reinforced Concrete, Mechanics and Design, by Wight and Macgregor, 6th edition-2012,
  12. Reinforced Concrete Fundamentals by Phil M. Ferguson, John E. Breen, James O. Jirsa, 5th edition -1988;
  13. Building Design and Construction Handbook, by Frederick S. Merritt, Jonathan T. Ricketts, 6th edition -2002, McGraw-Hill International Edition.

Reference Books #1
RC Books#2
RC Books #3