SPN's soil investigation and testing service covers everything from soil sampling with SPT, field and laboratory soil testing, to Boring Logs and reports signed by a COE-licensed engineer. We work on land, in rivers and offshore nationwide, so designers have real subsurface data before choosing foundations and piles.
Soil boring (soil investigation) means drilling to recover soil samples and running an SPT every 1.5 m to establish the soil layers, groundwater level and soil bearing capacity before foundations and piles are designed. SPN's service covers field testing, laboratory testing, over-water and offshore boring, and reporting. Owners, contractors and designers can use the same report for building-permit submissions.
Real projects published on our website, with links to the full write-ups
Drilling from a floating raft held by multiple anchors or spud legs, with steel casing through the water into the soil below the bed. Projects include rivers in Prachin Buri and Nakhon Pathom, under a bridge in Phra Nakhon Si Ayutthaya, in front of a dam in Kanchanaburi, and offshore work in the Gulf of Thailand.
Soil boring inside a petrochemical industrial estate in Rayong under the plant's work-permit and safety system; new factories and extensions (SPT + lab tests for machine and building foundations); an LPG port and fuel tanks in Chon Buri.
Deep soil boring to the bearing sand layer, with SPT and Shelby Tube sampling through Bangkok soft clay about 12–20 m thick.
Field in-situ testing measures and records soil properties directly on site. Some tests give readings immediately in the field; others recover soil, rock or concrete samples for further laboratory testing. SPN provides a complete service to ASTM / ISO standards, such as SPT · CPT · Vane Shear · Plate Bearing · Field Density · Field CBR · borehole permeability. Reports are certified by a COE-licensed engineer and can be used for the design of foundations, piles and embankments and for building-permit submissions.
The main test in soil boring, recording the N-Value every 1.5 m over the full depth for foundation and pile design. Suitable for a wide range of soils, both clay and sand.
A cone is pushed continuously into the ground, measuring tip resistance (qc) and sleeve friction (fs) to give a real-time soil profile without sampling. Suited to soft clay and silt.
Measures the in-place density and moisture of fill by the Sand Cone method to find % Compaction against the Standard or Modified Proctor. Used to accept earth fill, road pavement layers and slabs on grade.
Determines bearing capacity and the Modulus of Subgrade Reaction (k) for raft and strip foundation design
Measures the undrained shear strength (Su) of soft clay directly in the field. Suited to soils that are hard to sample without disturbance.
Soil density test by driving a steel rod, suited to roads, fill and large areas needing quick results. Read more about the Kunzelstab Penetration Test (KPT)
Tests the strength of pavement layers and subgrade and calculates CBR on the spot. Suited to roads and parking areas.
Pits 1–5 m deep dug by backhoe to inspect soil layers and existing foundations visually, take undisturbed samples for laboratory testing and run Field CBR in the pit. Suited to extensions, building repairs and hard-to-access areas.
Tests the California Bearing Ratio (CBR) directly in a test pit by pushing a standard piston and measuring load-penetration, for pavement and subgrade design of airports, roads and parking areas.
Takes concrete cores from existing structures to test compressive strength, check concrete quality and open inspection windows into the soil beneath existing structures.
Rock core sampling with an NMLC triple-tube core barrel and RQD calculation for large structures
Observation pipes installed in boreholes to measure and monitor groundwater level over the long term, for EIA work and projects that must control groundwater level.
Measures shear-wave velocity (Vs) and compression-wave velocity (Vp) in each soil layer to find Shear Modulus (G₀) and classify the Site Class per ASCE 7 for seismic design.
Measures apparent resistivity by the Four-Point Wenner Array method per ASTM G57 for grounding system design and corrosion risk assessment of buried pipes.
Measures soil thermal conductivity (λ) and thermal resistivity in the field by the Thermal Needle Probe method, for geothermal heat pump design and derating factors of underground power cables.
Measures the permeability coefficient (k) of the actual soil mass in a borehole by Falling / Rising Head and by Packer (Lugeon) tests in rock, for the design of dewatering systems, excavations, embankments and dams.
The rig is set on a floating raft or steel pontoon with steel casing through the water and soft soil, with SPT and Shelby Tube sampling for bridges, ports and dams — see over-water work details
Field in-situ testing measures and records soil properties directly at the project site. Many tests, such as CPT, Field Vane Shear and Plate Bearing, give readings immediately in the field without taking samples to a laboratory, so the parameters reflect real soil conditions at natural pressure and moisture. Others, such as SPT, test pits and rock/concrete coring, recover samples for further laboratory testing. The results are used to design foundations, piles, embankments and roads and for building-permit submissions to the relevant authorities. All tests are carried out to ASTM standards and certified by a licensed engineer.
SPN Soil Engineering provides complete field soil testing, grouped by purpose — tap to see the principle, standard and further reading for each test.
Tests used to determine soil properties for foundation and pile design and bearing capacity calculation, including:
Tests used for construction quality control and pavement design
← Scroll to see the full table →
| Test | Standard | Result | Used for |
|---|---|---|---|
| SPT Standard Penetration Test | ASTM D1586 | N-Value | Foundation & pile design |
| CPT Cone Penetration Test | ASTM D3441 / D5778 | qc, fs, Rf | Continuous soil profile |
| Field Vane Shear Test | ASTM D2573 | Su (kPa) | Soft clay shear strength |
| Plate Bearing Test | ASTM D1195 / D1196 | qu, k (MN/m³) | Raft / slab-on-grade design |
| Field Density Test (Sand Cone) | ASTM D1556 | % Compaction | Fill quality control |
| DCP Test | ASTM D6951 | CBR (%) | Pavement subgrade design |
| Light Penetrometer (Kunzelstab) | Following DIN 4094 (replaced by DIN EN ISO 22476-2) | N (blows/20 cm) | Quick density check |
| Test Pit | In-situ | Soil layers / samples | Soil & existing foundation survey |
| Rock Coring (NMLC) | ASTM D2113 | RQD (%) | Rock mass quality assessment |
| Concrete Coring | ASTM C42 | Compressive Strength (ksc) | Concrete quality of existing structures |
| Observation Well | In-situ | GWL (m) | Groundwater level monitoring |
| Downhole Seismic Test | ASTM D7400 | Vs, Vp (m/s) | Site Class / Shear Modulus G₀ |
| Electrical Soil Resistivity | ASTM G57 | ρ (Ω·m) | Grounding / cathodic protection design |
| Field CBR Test (In-Situ CBR) | Following ASTM D4429-09a (withdrawn by ASTM in 2018) | CBR (%) | Pavement design for airports, main roads |
| Soil Thermal Conductivity Test | ASTM D5334 | λ (W/m·K) | Geothermal design / cable derating |
| In-Situ Permeability (Falling / Rising Head, Lugeon) | ISO 22282-2 / 22282-3 | k (m/s), Lugeon | Dewatering, excavations, embankments, dams |
SPT and CPT are the two most widely used methods in soil investigation. SPT works in almost all soil types, including dense sand and hard soil (in coarse gravel the N-value may be overstated; rock is investigated by rock coring), recovers soil samples at the same time and costs less, but its results depend more on operator skill. CPT gives more continuous and consistent data with higher accuracy in clay and sand, but cannot penetrate gravel or rock. In practice the two are often used together, with SPT as the main method and CPT added where detailed data is needed.
Each type of project needs different soil data. Choosing the right tests reduces cost and delivers the parameters engineers need for design. SPN recommends test sets for 6 project groups: houses, high-rises and factories, roads and runways, dams and over-water work, projects on rock, and environmental and groundwater work.
Over-water / offshore boring means setting the drill rig on a floating platform, such as a raft or steel pontoon, held in position by anchors or spud legs, then installing steel casing through the water and soft soil before running SPT and taking soil samples to the same standards as on land. It is used for river bridges, ports, LPG terminals and dams.
Send us the location, building type and site plan (if any). SPN engineers will help set the number of holes, depth and test list, with a quotation within 24 hours.
SPN Soil Engineering provides laboratory testing to ASTM standards covering soil classification, shear strength, settlement, permeability, compaction and soil-cement, rock samples and soil chemistry, for the design of foundations, piles, roads, dams and other geotechnical work.
Soil laboratory testing analyzes the physical and engineering properties of soil samples recovered by soil boring in a laboratory with controlled conditions, giving accurate parameters for engineers to design foundations, calculate settlement, analyze slope stability and choose suitable construction methods. All tests are carried out to ASTM (American Society for Testing and Materials) standards and certified by a licensed engineer.
SPN Soil Engineering's laboratory tests are grouped by purpose as follows
Index & Physical Properties — soil classification per USCS and basic values for preliminary design
Determines soil moisture to assess in-situ condition and to calculate other parameters
Determines soil unit weight for calculating lateral earth pressure, settlement and stability
Used to calculate Void Ratio and Degree of Saturation
Sieve and sedimentation (hydrometer) analysis of particle size for fine-grained soil
Determines liquid limit, plastic limit and plasticity index for clay classification
Engineering Properties — parameters for foundation design, settlement calculation and stability analysis
Determines qu to calculate the undrained shear strength (Su = qu/2) of clay
Determines internal friction angle and cohesion for retaining wall and slope design
Gives shear strength parameters in both total and effective stress for stability analysis
Determines values to calculate the magnitude and rate of settlement of buildings on soft clay
Hydraulic & Erosion — for dams, embankments, excavations and dewatering systems
Fine-grained soil is tested in a flexible-wall permeameter; sand and gravel by constant head
Assesses whether clay is dispersive, which risks internal erosion in embankments and dams
Compaction, Subgrade & Stabilized Materials — quality control of pavement layers and cement-stabilized materials
Determines maximum dry density and optimum moisture content to set field compaction criteria
Determines subgrade bearing capacity for pavement thickness design
Compressive strength of soil-cement or cement-treated crushed rock specimens at the specified curing age
Rock Testing — used with rock coring for foundations on rock, dams and tunnels
Compressive strength of intact rock cores to assess foundation strength on rock
Quick rock strength test on cores or rock lumps to assess strength along the borehole
Soil Chemistry — assesses conditions affecting the durability of concrete, steel and buried metal pipes
Measures soil pH to assess conditions affecting corrosion of buried materials
Determines sulfate and chloride in soil to assess the risk to concrete and reinforcement of foundations and piles
Determines organic content of soil, e.g. peat or mud, which affects settlement and cement stabilization
← Scroll to see the full table →
| Test | Standard | Result | Used for |
|---|---|---|---|
| Natural Water Content | ASTM D2216 | w (%) | Soil classification, parameter calculation |
| Unit Weight / Bulk Density | ASTM D7263 | γ (t/m³) | Earth pressure, settlement calculation |
| Specific Gravity | ASTM D854 | Gs | Void ratio calculation |
| Grain Size / Sieve Analysis | ASTM D6913 / D7928 | % particle size | USCS soil classification |
| Atterberg Limits | ASTM D4318 | LL, PL, PI | Clay classification |
| Unconfined Compression | ASTM D2166 | qu, Su | Clay shear strength |
| Direct Shear Test | ASTM D3080 | c, φ | Retaining wall design |
| Triaxial Test (UU/CU/CD) | ASTM D2850 / D4767 / D7181 | c, φ, c', φ' | Stability analysis |
| Consolidation Test | ASTM D2435 | Cc, Cr, Pc, Cv | Settlement calculation |
| Compaction Test | ASTM D1557 | MDD, OMC | Compaction control |
| CBR Test | ASTM D1883 | CBR (%) | Pavement design |
| Permeability Test | ASTM D5084 / D2434 | k (m/s) | Dewatering, embankments, dams |
| Pinhole Test (Dispersion) | ASTM D4647 | Class D / ND | Embankment erosion risk |
| Soil-Cement UCS | ASTM D1633 | qu (ksc) | Soil-cement / cement-treated crushed rock |
| Rock UCS | ASTM D7012 | σc (MPa) | Foundations on rock |
| Point Load Test | ASTM D5731 | Is(50) | Rock strength along the hole |
| Soil pH | ASTM D4972 | pH | Corrosion assessment |
| Sulfate & Chloride | ASTM C1580 / AASHTO T 291 | SO₄, Cl (%) | Concrete & reinforcement durability |
| Organic Content | ASTM D2974 | OC (%) | Peat, mud, ground improvement |
The SPN Soil Engineering laboratory tests to ASTM standards. All test equipment is calibrated at the specified intervals. Every test report is checked and signed by a COE-licensed civil engineer and can be used for building-permit submissions, project loan applications with banks, and engineering certification to the relevant authorities.
From the day you send project details to the certified report — read the duration of each step in How many days does soil boring take?
Provide the location, building type or number of storeys and site plan (if any) by phone, LINE or email
Engineers set the number of holes, depth and tests suited to the project, with a quotation within 24 hours
SPT every 1.5 m, SS / ST sampling and groundwater level measurement, on land and over water
Samples tested to ASTM standards; basic tests take about 3–5 days
Boring Log and Soil Profile prepared with lab results, checked and signed by an engineer
Report within 10 days for jobs of up to 3 holes, for design and building-permit submissions
Every report shows the soil layers, SPT N-Values, groundwater level and lab test results, certified by an engineer. Read more: How to read a Boring Log and Interpreting SPT N-Values
Soil boring for a 2–3 storey house starts at about 20,000–40,000 THB for the whole job (2–3 holes incl. basic lab tests and a report certified by a licensed engineer). We work nationwide from our office in Samut Prakan.
| Job type | Typical scope | Starting price |
|---|---|---|
| 2–3 storey house | 2–3 holes · 20–30 m deep | 20,000–40,000 THB |
| 3–4 storey commercial building | 3–4 holes · 25–30 m deep | 30,000–70,000 THB |
| Factory / warehouse (~1,000 m²) | 4–6 holes · 30–40 m deep | 40,000–150,000 THB |
| Field soil testing Plate Bearing · Field Density · DCP | Priced by number of points and working days | See how prices are calculated |
The prices above are approximate starting prices, including field work, basic lab tests and a report certified by a COE-licensed engineer. They exclude travel and equipment mobilization costs, which depend on site distance. Actual prices depend on the number of holes, the depth needed to reach hard strata and site conditions — see the full table with regional travel costs at Soil Boring Prices 2026
SPN's soil boring crews and engineers work from our office in Bang Sao Thong, Samut Prakan, and regularly cover the following areas
Real projects in the gallery above: Bangkok condominium · Factories and petrochemical estate, Rayong · Deep excavation, Chon Buri · River boring in Prachin Buri, Nakhon Pathom and Phra Nakhon Si Ayutthaya · Srinagarind Dam, Kanchanaburi · Offshore boring in the Gulf of Thailand
Send your site location for a free quotation within 24 hoursOne hole 15-30 m deep takes 1-2 days. A typical job of 5-10 holes takes 3-7 days, depending on site conditions and soil layers.
A report showing the soil layers over the full depth, with soil type, SPT N-Values and groundwater level, used for foundation and pile design.
For a 2–3 storey house, prices start at about 20,000–40,000 THB for the whole job (2–3 holes, 20–30 m deep, incl. basic lab tests and a report certified by a licensed engineer). Commercial buildings and factories cost more, depending on the number of holes and the depth needed to reach hard strata. Prices exclude travel and equipment mobilization costs, which depend on site distance. See the starting-price table above or the detailed table at Soil Boring Prices 2026, and request a free quote at +66 64 746 9601.
Provide the location, number of holes, depth and project type, e.g. house, building, factory or road.
Yes. Every report is signed by a licensed engineer and can be used for building-permit submissions and bank applications.
Yes, nationwide across all 77 provinces. Our office is in Bang Sao Thong, Samut Prakan, so we reach sites in Bangkok and its vicinity fastest, and we work regularly in the East/EEC (Chon Buri, Rayong, Prachin Buri) and the Central region (Phra Nakhon Si Ayutthaya, Nakhon Pathom, Kanchanaburi), as well as in rivers, at sea, at dams and in industrial estates. Travel and equipment mobilization costs are added based on site distance.
SPT recovers soil samples and works in almost all soil types, including dense sand and hard soil that CPT cannot push through (in coarse gravel the N-value may be overstated; rock is investigated by rock coring), and it costs less. CPT gives more accurate continuous data in clay and sand but cannot pass through gravel. In practice the two are often used together.
It measures the in-place density of compacted fill (ASTM D1556) and compares it with the Maximum Dry Density from the Standard or Modified Proctor test to check that the fill meets the % Compaction specified by the engineer.
It determines soil bearing capacity and the Modulus of Subgrade Reaction (k) for the design of raft foundations, strip foundations and slabs on grade. It suits projects where foundations bear directly on soil.
The Downhole Seismic Test (ASTM D7400) measures shear-wave velocity (Vs) and compression-wave velocity (Vp) of soil layers in a borehole to calculate Shear Modulus (G₀) and classify the Site Class per ASCE 7. It suits petrochemical plants, power plants and buildings requiring seismic design.
The soil electrical resistivity survey (ASTM G57) uses the Four-Point Wenner Array method with 4 electrodes to measure the apparent resistivity (Ω·m) of soil. It is used to design grounding/earthing systems for substations and factories and to assess the corrosion risk of buried metal pipes (Cathodic Protection).
Basic tests 3-5 days, Consolidation Test 7-14 days, Triaxial Test 7-10 days, depending on the number of samples.
Yes. SPN performs soil boring in rivers, under bridges, in front of dams, at ports and in the Gulf of Thailand. The rig is set on a floating raft or steel pontoon, held in position by anchors or spud legs, with steel casing through the water and soft soil, then SPT and Shelby Tube sampling are carried out to the same standards as on land. Prices depend on water depth, current and equipment transport, so they are estimated per project.
Laboratory tests on soil samples per ASTM D5084 (fine-grained soil) or ASTM D2434 (sand and gravel) give the k of that sample. Borehole tests by Falling / Rising Head (ISO 22282-2) or Packer / Lugeon in rock (ISO 22282-3) give the value of the actual soil mass, including the effect of sand seams and fractures. Excavation and dewatering work often uses both together.
Soil with high sulfate or chloride, or acidic soil, can deteriorate the concrete and reinforcement of foundations or piles quickly and accelerate corrosion of buried metal pipes. Results of pH (ASTM D4972), sulfate and chloride (ASTM C1580 / AASHTO T 291) tests support the design engineer's choice of materials and protective measures.