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Guides, articles and technical know-how on geotechnical engineering, soil investigation, pile testing, topographic surveying, structural inspection and foundation design from the SPN Soil Engineering team of engineers.
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Concrete Floor Cracks: How to Survey Them, with a 23-Point Crack Map and Site Photos
Existing Concrete Floor Inspection: What to Check, with a Real Case Study and 3D Model
What Is a Flood Study? Steps for Assessing Flood Risk Before Building a Project
Case Study: Floor Load Test Before Building Alteration, Water Ponding to 64 cm, Thung Khru
How to Read Pull-Out Test Results — Load–Movement Curves from 23 Real Test Points
Reading GPR Rebar Scan Results — Column Bar Count, Tie Spacing, Concrete Cover
Case Study: Parallel Seismic to Find Existing Pile Lengths + Soil Boring at a Samut Prakan Factory
What Is a Soil Thermal Resistivity Test? Soil Thermal and Ambient Temperature Testing (ATT) for Underground Power Cables
How Long Does a Static Load Test Take? From Booking to Final Report
Failed Static Load Test? Pass/Fail Criteria and Corrective Steps
Case Study: Slope Inclinometer at Kraseaw Hydropower, Suphan Buri
Case Study: 8 m Piezometer and Monitoring Well in Samut Prakan
Case Study: Deep Settlement Points at the Grandio Bang Na Km 5 Project
Case Study: Inclinometers for a Deep Excavation in Bang Phli on Bangkok Soft Clay
Which Work Requires a Senior Professional Engineer's Signature? A Checklist Before Hiring
Senior Civil Engineer Promotion: Eligibility, Portfolio and How to Prepare
What Is a Senior Professional Engineer? How It Differs from a Professional Engineer and Who Needs One
Soil Investigation and Pile Testing in Greater Bangkok — Real Projects on Soft Clay
Soil Investigation and Pile Testing in Chon Buri–Rayong (EEC) — Real Projects in Industrial Estates
Field Soil Testing Prices 2026 — How Plate Bearing, Field Density and DCP Are Priced
Buying Vacant Land? Should You Do Soil Boring First to Know the Real Cost Before Transfer
SS vs ST Soil Sampling: Understanding Split Spoon and Shelby Tube
How Many Soil Boring Methods Are There? Wash Boring, Rotary Drilling and Hand Auger Compared
How to Prepare the Site Before Soil Boring: An 8-Point Checklist from Our Survey Team
Manual vs Automatic (Real-Time) Monitoring: Differences and Which to Choose
When Is Instrumentation Required? Which Projects Need It
Settlement Points and Tiltmeters: Measuring Settlement and Tilt of Adjacent Buildings
Strain Gauges in Geotechnical Work: How to Measure Forces in Struts and Piles
Settlement Plates: Monitoring Settlement of Fills and Embankments
Deep Excavation Monitoring in Bangkok Soft Clay: What Needs to Be Measured
What Is a Piezometer? Measuring Pore Water Pressure (Standpipe vs Vibrating Wire)
What Is an Inclinometer? Measuring Lateral Movement of Soil and Retaining Walls
What Is an Observation Well? Groundwater Level Monitoring Wells and How They Are Installed
What Is Geotechnical Instrumentation? 10 Types Used in Practice
Preparing the Site for a Plate Bearing Test: A Checklist for Contractors and Site Supervisors
Structural Steel Weld Testing: UT, MT, PT or RT — Which Method to Choose
Bridge Load Testing: How Is the Load Capacity of Special Structures Tested?
Pre-Construction Survey of Adjacent Buildings: Preventing Crack Disputes with a Dilapidation Survey
Building Inspectors for the 9 Building Types vs Structural Testing: What's the Difference?
How Much Load Can a Factory or Warehouse Floor Carry, and How Is It Proven?
Structural Inspection Before Buying or Leasing a Building or Warehouse: What Should Be Checked?
Structural Inspection & NDT Prices 2026: What Drives Cost and Starting Rates
Which Structural Cracks Are Dangerous? How to Read Them and Crack Monitoring
Post-Earthquake Building Inspection: Green, Yellow and Red Tags Explained
Concrete Compressive Strength Below Spec? What to Do: Steps and Core Testing
Can PDA Test Bored Piles? High Strain Testing of Cast-in-Place Piles
DPT Pile Testing Standards: What Do They Cover? 1106 · 1251 · 1252 · 1551
Preparing Pile Heads for PDA and Seismic Testing: A Site Checklist
How to Inspect Welded Joints in Spun Piles and Micropiles: 5 Defects to Check
Pile Testing Standards Update 2026: Which ASTM Standards Were Withdrawn and What Replaces Them
Negative Skin Friction: Why Piles Still Settle After Passing Load Tests
How Much Load Can a Pile Group Carry? Group Efficiency and Block Failure
What Is an Instrumented Static Load Test? Separating Shaft Friction from End Bearing
Thermal Integrity Profiling (TIP): Testing Bored Piles with Heat
What Is Wave Equation Analysis? Selecting the Pile Hammer Before Mobilization
What Is a Rapid Load Test (Statnamic)? The Middle Ground Between PDA and Static Load Testing
What Is a Soil Resistivity Test? Soil Electrical Resistivity for Solar Farms, Gas Pipelines and Data Centers
What Pile Tests Does a Solar Farm Need? Uplift, Lateral Load and Soil Investigation
Piles Refusing Above Design Depth? Identify the Cause Before Deciding
What Is a Lateral Load Test on Piles? Where It Is Used
What Is a Pile Uplift Test? How It Differs from a Pull-out Test
Pile Driving Cracked the House Next Door? Vibration Monitoring
Buying a Used Factory or Warehouse? How to Check Its Piles and Foundations
Test Pile vs Working Pile — What's the Difference?
What Is Blow Count? Last 10 Blows Criteria for Stopping Pile Driving + Criteria Table
Bored Piles vs Driven Piles: How Does Testing Differ? Matching the Method to the Pile Type
Kentledge vs Reaction Piles — Which Static Load Test Setup Is Better?
What Is Cross Hole Sonic Logging (CSL)? Integrity Testing of Large Bored Piles
What Is a Restrike Test? Why PDA Testing Is Repeated After Pile Driving
What Is a Bi-Directional Static Load Test (O-cell)? Testing High-Capacity Bored Piles
Does the Law Require Pile Testing? Test Criteria Under the 2023 Foundation Regulation
What Should a Pile Test Report Include? A Checklist Before Applying for a Building Permit
What Causes Pile Defects? 6 Causes of Pile Damage and How to Detect Them
How to Choose a Pile Testing Company: 7 Things to Check Before Hiring
How Many Days Does a PDA Test Take? Timeline from Booking to Report
Micropiles for a House Extension: Do They Need Pile Testing?
What Is a BOQ? How a Quantity Take-off Estimate Differs from a Per-m² Price
Thai Engineer License Grades: What Can Associate, Professional and Senior Engineers Sign?
What Can an Associate Civil Engineer Sign? Full Scope Table
Designing RC Roads in Developments and Housing Estates: Thickness, Pavement Layers and Standards for 2026
Designing Drainage Systems and RC Pipes in Developments: Components, Pipe Sizing and Standards for 2026
Earthquake-Resistant Building Design Under the 2021 Ministerial Regulation and DPT 1301/1302-61, Simply Explained
What Are Structural Calculations? Which Buildings Need Them and Who Can Certify Them
RC Structural Design and Full-Service Civil Engineering — The Complete 2026 Guide
How Are RC Structural Design Fees for Houses and Buildings Priced? Methods and Cost Factors for 2026
Site Plans, Earth Filling and Site Grading — Planning to Avoid Settlement and Flooding in 2026
House Building Permits 2026 — Steps, Required Documents and Where to Apply, Simply Explained
What Is Rock Coring? Procedure, Equipment and RQD
How Tall Can a Retaining Wall Be Before It Needs an Engineer's Design and Sign-Off?
Retaining Wall Budgets: What Drives the Price + Precast vs Cast-in-Place
Can Existing Building Foundations Be Strengthened After an Earthquake?
Foundations for House Extensions: How to Avoid Settlement and Cracks — Structural Separation + Micropiles
What Is Deep Soil Mixing (Soil-Cement Columns)? When to Use It and How It Differs from Concrete Piles
What Causes Landslides? 5 Warning Signs + How to Protect Hillside Homes
Retaining Wall Design on Soft Clay in Bangkok and Its Vicinity
Hillside Cut-and-Fill Earthworks and RC Retaining Walls: A Case Study in Northeastern Thailand
Temporary Earth Retaining System for a 4 m Deep Excavation — Case Study, Khon Kaen
Which Retaining Wall Should You Choose? 7 Types Compared, an Engineer's Guide
How Many Ground Improvement Methods Are There? 8 Ways to Improve Soft Soil Before Construction
What Is a Spread Footing? How It Differs from a Pile Foundation and Which to Choose
Seismic-Resistant Foundations on Soft Soil: How Are They Designed?
Fill Settlement: How to Fix It — Causes, Prevention and When to Call an Engineer
How Do PVD and Preloading Improve Soft Soil? Accelerating Settlement Before Construction
What Is the Factor of Safety in Slope Stability? What Value Is Safe
Preventing Riverbank Collapse: How to Design Waterfront Retaining Walls
What Is a Topographic Survey? Process, Deliverables and Duration
GPS RTK vs Total Station vs Drone: Which Survey Method Should You Choose?
ASTM D5882, D4945, D1143: What's the Difference? 3 Pile Testing Standards Explained
What Is CAPWAP? Why PDA Results Are Not Complete Without CAPWAP Analysis
How Many Types of Pile Testing Are There? All Methods: Seismic · Dynamic (PDA) · Static
At What Concrete Age Can Piles Be Tested? How Long to Wait Before Testing
Pile Failed a Seismic Test? Next Steps for Investigation and Remediation
The 2023 Foundation Regulation Simply Explained: What Project Owners Need to Know
Soil Investigation Reports for Building Permits: What They Must Include — A Legal Checklist
No Soil Boring? What Soil Bearing Values the Law Allows
Soft Clay, Stiff Soil, Hard Stratum: How the Law Classifies Soil by SPT Value
When Does the Law Require a Plate Bearing Test? The 200 kPa Criterion
What to Do About Eccentric Piles? The 75 mm Criterion Under the 2023 Ministerial Regulation
Retaining Walls Under the 2023 Ministerial Regulation: The 3 FS Checks That Must Pass
How Much Load Can a Pile Carry by Law? The 40/50/40 Criteria in the 2023 Foundation Regulation
How Many Boreholes and How Deep? Guidelines by Building Size
How Long Does Soil Investigation Take? Timeline from Booking to Report
How to Choose a Soil Investigation Company: 7 Things to Check Before Hiring
Soil Investigation for Warehouses and Factories: How It Differs from Houses
House Settlement and Extensions: Why Do a Soil Investigation First?
What Laboratory Soil Tests Are There?
Field Vane Shear Test: Measuring Soft Clay Strength In Situ
What Is Soil Bearing Capacity?
How Does Groundwater Affect Foundations? 4 Key Impacts
Earthquakes and Foundations: Which Soils Are Prone to Liquefaction
Spalling Concrete and Corroded Rebar: How to Assess and Repair
What Is a Chloride Content Test? Measuring Chloride in Concrete of Coastal Buildings
Building After a Fire: Repair or Demolish? Assessing Heat-Damaged Concrete
Non-Destructive Testing (NDT) of Concrete Structures: What Methods Are There? The Complete Guide
How to Run a Rebound Hammer Test on Site for Reliable Results: A Practical Guide to DPT 1502-51
What Is a Rebound Hammer Test? Estimating Concrete Compressive Strength per ASTM C805
What Is a UPV Test? Assessing Concrete Quality and Cracks with Ultrasonic Pulses per ASTM C597
How Does UPV Measure Concrete Crack Depth? Formula and Limitations
Low UPV Test Results: What Do They Mean? How to Read Them and Confirm
What Is a Pull-Out Test? Testing Chemical Anchors and Threaded Studs per ASTM E488
Floor Load Test: Which Loading Method? Water Ponding vs IBC Tanks vs Sandbags
What Is a Floor Load Test? Testing Slab Strength with Real Loads per ACI 318-19
What Is GPR Concrete Scanning? Locating Rebar, Voids and Embedded Pipes Non-Destructively
What Is a Cover Meter / Rebar Scanner? Locating Rebar and Measuring Concrete Cover
What Is Half-Cell Potential? Assessing Rebar Corrosion in Concrete
What Is a Carbonation Test? Measuring Carbonation Depth to Assess Concrete Service Life
NDT vs Core Test: What's the Difference? Choosing a Concrete Inspection Method
Before Extending or Changing the Use of an Old Building: What Structural Checks Are Needed?
What Is Impact Echo? Locating Voids and Measuring Concrete Slab Thickness per ASTM C1383
What Is a Parallel Seismic Test? Finding the Depth of Existing Piles and Foundations with No Records
What Is a Concrete Core Test? Drilling Cores to Test Actual Compressive Strength per ASTM C42
What Is the DCP Test? Dynamic Cone Penetrometer, CBR Correlation & Reference Tables
DCP vs KPT vs SPT — Which Soil Test Suits Your Project?
What Is the Kunzelstab Penetration Test (KPT)? Light Dynamic Probing
What Is a Static Load Test? Method, Reading the Curves + Standards
How Many Piles Should Be Tested? Sampling Criteria Engineers Actually Use
What Is a Dynamic Load Test (PDA)? Procedure, Standards and Duration
Seismic Test for Pile Integrity (Low Strain)
Field Density Test Failed? Causes and On-Site Fixes
Field Density Test: Measuring In-Situ Soil Density
Plate Bearing Test: Testing the Bearing Capacity of Soil
Soil Boring Over Water and at Sea — Challenging Case Studies
How to Read Seismic Integrity Test Results — Interpreting Reflectograms and Defects
How to Read Static Load Test Results — Load-Settlement Curves and Davisson
How to Read PDA Test Results — A Dynamic Load Test Analysis Guide
Before Buying Land for a Factory — An Engineer's Soil Checklist
ASTM Standards for Soil Investigation — A Complete Comparison Table
5 Warning Signs of House Foundation Problems — Check Before It's Too Late
How Many Types of Piles Are There? Driven, Bored and Spun Piles Compared
How to Interpret SPT N-Values: An In-Depth Guide for Engineers
Do You Need Soil Boring for a 2-Storey House?
Pile Testing Prices 2026 — Seismic, PDA, Static: How Much per Pile?
House Soil Boring Prices 2026 — A Budget Calculation Guide
Bangkok Soft Clay vs Upcountry Soils — Why Foundation Design Must Differ
What Is Soil Investigation? Why Do It Before Building a House?
Dynamic vs Static Load Test: Which Should You Choose?
