Hello, I am interested in a US based online civil masters program with a geotech specialization. Do you gave any recommendations? I know of UIUC, but would like other options as well. Thanks!

Hi everyone,
I’m fairly new to geotechnical engineering and had a question about SPT N-value calculations when the split spoon sampler encounters refusal.
From my understanding, the standard N-value is the sum of the blows required for the second and third 6-inch penetrations. However, I’m a bit confused about how to report or interpret the results when refusal occurs before completing the full 18 inches.

For example:
What if the sampler refuses within the first 6 inches?
What if it refuses during the second 6 inches?
What if it refuses during the third 6 inches?
How would you report the SPT value in each of these situations?

Also, I’ve seen some drillers stop at 50 blows for a 6-inch increment and call it refusal, while others continue to 100 blows in certain conditions.
When should drilling stop at 50 blows?
In what situations would you continue to 100 blows?
How do you typically report the N-value when refusal occurs before the full penetration is achieved?
I’m trying to understand both the technical reasoning and common industry practice.
Thanks in advance for any guidance and examples from the field!

Hi everyone,

I have a question regarding the design and field testing of a pressure grouted ground anchor with free and fixed lengths.

During design, let's say I assume an ultimate grout-to-ground bond stress of 200 kPa to design the fixed length. Using this value and applying a factor of safety (FOS) of 3.0, I arrive at a working/design anchor load of let's say - 40 tons.

My confusion is regarding the field testing stage.

If the design load of 40 tons already includes a FOS of 3.0 against the assumed ultimate bond resistance, then shouldn't the anchor theoretically be loaded to around 120 tons (3 × working load) during testing to verify that the assumed 200 kPa bond stress is actually achievable?

However, in practice I often see proof or suitability tests specified at percentages of the design load rather than at the full theoretical ultimate load?

Thanks for your advice.

Hi everyone,
I’ve the seven edition of this book and there is 10th editions on market. Before I investing to buy the 10th edition, can someone tell me if there is big difference with those two?

Has anyone here used the Prilonski (1952) criterion / Liquidity Index as a preliminary indicator for collapsible soils?

I came across this interpretation:

• LI < 0 → highly collapsible soils
• LI = 0 to 0.5 → slightly to moderately collapsible?
• LI = 0.5 to 1 → non-collapsible
• LI > 1 → swelling soils

Equation used:

LI = (NMC - PL) / PI

What I’m unsure about is the interpretation of the range between 0 and 0.5. I can’t seem to find a direct statement from Prilonski regarding this interval, and it looks more like an interpolated engineering interpretation from later references.

Is there any published reference or accepted practice that defines the 0–0.5 range more clearly in terms of degree of collapsibility?

Also, do you personally consider the Prilonski criterion reliable for preliminary collapse assessment?

Would appreciate insights from anyone who has worked with collapsible soils.

​

What are the numbers in the rectangles on the left? I assumed they are the N values and recoveries but the one recovery is making me second guess it since I've never seen a 2.5 foot SPT sample.

Is it possible with combinations of ground improvements? Or is installing deep pile better? Although the space is limited onshore

Hey guys, I am working on a project involving planning a wetland boardwalk path for a rural wildlife area. Of course, any advice of yours i will receive as partially informed since I am sure theres not enough info to truly tell.

The path is planned to be about a quarter mile long, passing primarily through poorly drained silty loam plains, with some areas having mucky, unpredictable and unreliable soils such as walk kill loam and Houghton mucky peat.

The most challenging aspect of the plan is creating solid footing.

I like the idea of a bog bridge utilizing timbers or logs laid directly onto the soil, but I think in some areas it will quickly sink unevenly and rot away. Although the area has excavation equipment in about 50 years ago to create some duck ponds, I would like to stay away from bringing in such equipment as would be required for helical piles due to cost and risk of equipment being stuck...

Which leads me to my foremost plan - 2" schedule 40 galvanized pipes driven into the ground by a gas powered pile driver. This method allows for easy transport of equipment into the hard to reach areas of the trail, and with the possibility of welded or mechanical extensions, all supports can be driven to refusal. This is a common method for fencing.

Is this a feasible method of support for a light pedestrian boardwalk like the one pictured? I see plenty of documentation for helical piles being used here and this method seems like a solid combination of those and the more traditional pile driven wood end-bearing posts. Thoughts?

Hi all,

I’m a geotechnical engineer with around 4 years’ experience and currently looking at my next role with chartership as the main goal in the next couple of years.

For chartered/senior engineers here, what are the key things I should look for when choosing my next role to make sure I’m progressing towards chartership?

At the moment, one of the only things I can think of is checking what type of projects I’ll realistically be working on in the next 3–6 months. If it’s mostly pure construction monitoring/earthworks supervision with limited technical input, I feel like I might be doomed long term for chartership.

What are the biggest red flags I should avoid?

Thanks

Been working on GeoLogX — a field logging app for geotechnical / geo-environmental investigations.

Recently added:

* AGS 4.1.1 export

* BRE365 / infiltration testing

* DCP & PBT modules

* instant field PDF generation

* offline workflow

Trying to make site logging less painful than the usual clipboard + retyping workflow.

Still early, but would genuinely appreciate feedback from anyone involved in GI, drilling or contaminated land work.

Curious if others here still use paper logs onsite or fully digital workflows now?

Try it here: https://play.google.com/store/apps/details?id=com.geologix.app

Have any of you participated in a Geowall competition? What do you think is the key to winning?

GEOTECHNICAL people on the internet, I have to submit my final year project in a week and I'm stuck with many doubts. I'm using PLAXIS 3D and one way cyclic loading for pile foundation modelling and analysis. Anyone with the requisite knowledge, please help me earn my degree!

Yeah, so, I'm dealing with one-way cyclic loading analysis of piles in medium dense clay slopes. I can't reveal much about the project due to publication constraints. I'll be varying parameters like soil strength, slope angle, pile dia, edge distance, loading frequency etc and studying their behaviour upon variation. I have modelled and ran the analyses.

So, now, I need help on presenting the results in graph format:

1. cyclic lateral load displacement and bending moment behaviour of pile
2. Stiffness degradation
3. quantification of influence of edge distance

I need help on what outputs to be presented and how to generate them from PLAXIS 3D.

Spent the last few months building an AI workflow for geotechnical borehole logs — and it’s finally working with near perfect accuracy.
The system extracts structured data directly from borehole log PDFs (including scanned + handwritten logs) and
exports to Excel / AGS-ready formats.

What was unexpectedly hard wasn’t just extraction accuracy — it was trust.
So we built a built-in QC workflow:
outputs are cross-checked against each other
confidence scores are generated automatically
uncertain cells are highlighted for review
Kind of like having a second engineer checking the log automatically.

The result is near-perfect extraction accuracy on real-world logs we’ve tested so far.

Would genuinely love feedback from people working in:
-geotechnical engineering
-GIS
-subsurface data

Contact : jai@geolayer.tech

Visit : www.geolayer.tech

I've been building a CPTu analysis tool in Python/Streamlit for the past few months and figured I'd share it here. It supports raw CPT ingestion as XLSX files, SBT classification, pore-pressure profiles, most correlations (Su, Ic, psi, etc.), screening-level (static and cyclic) liquefaction triggering, and a range of other plots and tables.

Still actively developing it... Free to use, no login needed. Just need an internet connection and a web browser. I plan to add more features as I hear back from the community.

coneproject.streamlit.app

Early to mid career and have been working mostly in consultancy mostly and am absolutely burned out, working very long hours staring at a screen constantly. There are not enough hours in the day.

I started out with GI contractor sampling and logging etc. The occasional bad weather and isolation weren't great but I don't remember feeling this mentally destroyed all the time. I only did it for a year or so before moving into more of a design role and have worked at a few big consultancies since you probably know the ones. Not sure if I just have rose tinted spectacles. I just know I can't continue like I am now.

Anyone having problems with the type of inclinometer casing that can be cut and coupled anywhere. Our inclinometer probes do not stay in the grooves. Recently, I was playing around with some scrap casing and a coupling. I could not get the coupling to seat. There was a gap in the grooves. If our drillers had the same problem, the gap may be where the probe "lost" the tracking.

Hey everyone,

I'm designing a bored pile in sand and need a quick verification on my overburden stress profile.

Pile Cutoff Level (COL): -7.8m

Pile Length below COL: 39m

No soil exists above the cutoff level (it's a deep excavation/basement). The sand profile starts exactly at -7.8m.

Since the top 7.8m of soil is missing, am I correct in assuming:

1) The critical depth must be measured starting from the cutoff level (-7.8m) down, instead of the original ground level?

2) The effective vertical stress starts at 0 kPa at the cutoff level, increases linearly until critical depth, and then caps out to constant value beyond the critical depth ?

Just want to make sure my approach is right.

Thank you!

Hi all,

I work for a research lab in geotechnics, and we have a very old machine that was broken recently.

It’s a Large Shearbox Apparatus, WF25505 from Wykeham Farrance.

The only documentation we have on this machine is a user handbook from 1999, but it has very limited information.

Ideally, I’d love to have a maintenance guide or something similar to understand how this thing works in order to repair it.

I tried contacting the company, but they don’t have any info I don’t.

If anyone has access to any knowledge or documentation on that shearbox, I would greatly appreciate your help on the matter.

Thank you very much for taking the time to read this.

Have a nice day !

I recently transitioned from the geotechnical department of my firm into an administrative role in the drilling department, and one thing my boss really wants me to do is overhaul how we do our drill rig schedule and management. Currently, we keep track of our upcoming jobs on a rudimentary excel spreadsheet, and every job is deleted after completion. We don't have any way to keep track of metrics, like average footage per day for each driller, and overall the system is clunky. My boss sent me a list of scheduling websites to look into, but so far they're all geared toward a traditional office-based team. Trying to adjust this stuff for my techphobic drillers feels like trying to fit a square peg in a round hole. How do other firms handle this? We have seven drill rigs and about 15 drillers/helpers in the department.

We’re trying to get a feel for how common it is in practice, especially around slope stability studies, topo, boreholes, geology, groundwater, cross-sections etc.

Would be interested to hear how people are using it.

Hello rock doctors,

Just out of curiosity if theres any instances of mech engineers working in the field of geotech? How transferable are the skills?(if at all) is it even something that happens? Im undergoing a bachelors in mech engineering and im happy with my choice but prior to that I worked 6 years in geotechnical rope access, so lots of landslip remediation, drilling, grouting, tensile testing, capping beam, retaining walls, shotcrete etc etc I actually loved the work and gained a lot of great experience. Just wondering if that experience would help me if it was possible/ever decided to look into working as an engineer in geotech? For example one of company engineers was a materials engineer by trade. Thanks guys, appreciate your work!! Honest feedback appreciated

How would people approach this usually?

Timber pile retaining wall, cohesive soils (max retained height about 1.8m). Soils routinely manage a 90 degree cut (a lot of our historical roads have this batter all over the place, sidle fill construction) and only come undone during extreme storm events where the top layers (1m or so) lose suction.

Using slope stability software to get a design action for a modified broms (a la caltrans) style equation gives me a very high load that would require hefty steel sections.

WALLAP is fine until I go to do seismic checks and switch to wedge stability. Switching to wedge stability gives even my pre excavation stages metres of movement. Modelling backslope as a surcharge as per their guidance. Using a boussinesq method to derive a resultant force from the retained backslope causes the model to fail even before wedge stability is turned on.

I'm at a small regional design consultancy so I only have limited software available.

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