Pictures courtesy of Daily News

 

Workers and officials in Bangkok are racing to stabilise a massive sinkhole on Samsen Road that has left the new Samsen Police Station at risk of collapse. The incident, which occurred on the morning of 24 September, forced the evacuation of police officers and residents amid fears of further subsidence. Authorities have since deployed sandbags, crushed stone and monitoring equipment to reduce risks and prevent additional damage.

The sinkhole, measuring around 30 metres wide, 30 metres long and 50 metres deep, formed after a tunnel housing the Purple Line extension collapsed. The shift caused soil to slide into the underground station at Vajira Hospital, while broken pipes allowed water to flood the area, worsening the erosion. More than 50,000 sandbags have already been dropped into the hole to plug the cracked tunnel, to prevent soil and water entry into railway construction site, which should limit further soil loss and collapse.

 

Bangkok governor Chadchart Sittipunt confirmed that Vajira Hospital remains relatively secure due to underground concrete retaining walls. However, the five-storey Samsen Police Station building lacks such reinforcement. Large amounts of soil beneath its foundation have shifted, and two of its pillars have already disappeared, leaving the structure at significant risk.

 

Laser monitoring devices have been installed to track structural movement at the police station, while traffic restrictions have been imposed on nearby roads. Authorities have also warned that further bans may be necessary if the ground continues to shift. Residents of about 20 households, including elderly and bedridden people, were relocated as tap water and internet services were disrupted in the area.

 

Prime Minister Anutin Charnvirakul inspected the site twice on 24 September, accompanied by ministers and senior officials. He expressed concern about the impact of heavy rain on the fragile ground, apologised to the public for the disruption, and pledged that the government will maintain oversight until the situation is resolved. He also highlighted the difficulty of removing four 30-tonne concrete blocks obstructing the tunnel.

 

Multiple agencies, including the Mass Rapid Transit Authority of Thailand, the Disaster Prevention and Mitigation Office, and construction contractor Ch. Karnchang Plc., are coordinating stabilisation works. Officials stated that reinforcement measures are being developed for vulnerable structures.

 

Key Takeaways

 

• A massive sinkhole on Samsen Road has put the new Samsen Police Station at risk of collapse.

• Authorities have deployed sandbags, crushed stone and laser monitoring to prevent further subsidence.

• Prime Minister Anutin pledged accountability and government oversight until the situation stabilises.

 

Related Stories

 

Massive-road-collapse-near-vajira-hospital-triggers-evacuation

 

  Adapted by Asean Now from Dailynews 2025-09-25

 

 

 

 

Sandbags?

 

 

They are currently blaming shifting ground soil as the source of the sinkhole. However, I am curious about that being the real reasoning behind the sinkhole since there is currently underground construction being done right next to the sinkhole. 

Just now, thesetat said:

They are currently blaming shifting ground soil as the source of the sinkhole. However, I am curious about that being the real reasoning behind the sinkhole since there is currently underground construction being done right next to the sinkhole. 

 

 

I wondered of there's been a massive unground water leak from this pipes that caused erosion.

Unnecessary comment removed 

 

@Gottfrid

3 hours ago, Will B Good said:

 

 

I wondered of there's been a massive unground water leak from this pipes that caused erosion.

Looks like the tunnel construction beneath is to blame 

 

 

 

 

Dang man.  That's a lot of sandbags.  They may need to re-open the Cambodian border to find enough labor to fill that many.

 

(And yes...  I am taking a whizz there)

 

UPDATE
Concrete Plan to Seal Tunnel Before Rainfall

 

Picture courtesy of Daily News

 

Bangkok authorities have altered repair plans to urgently seal a collapsed tunnel entrance on Samsen Road, before heavy rainfall. The adjustment comes after attempts to lift concrete slabs failed, prompting a shift to pouring concrete and covering it with sand.

 

The change was confirmed on 25 September by Mr Suriyachai Rawiwan, Director of the Bangkok Metropolitan Administration’s Department of Disaster Prevention and Mitigation. The original plan, ordered by Governor Chadchart Sittipunt, involved using cranes and slings to lift concrete slabs. However, the slabs could not be lifted due to resistance from soil and structural debris within the tunnel. As a result, the Mass Rapid Transit Authority of Thailand (MRTA) and construction company Ch. Karnchang opted for an alternative method.

 

The revised plan involves pouring concrete directly to form a platform about three metres high to seal the tunnel entrance. Once set, sand will be packed over the concrete to reinforce the surface. This approach will also help support the structure of the nearby Samsen Police Station, which is adjacent to the collapse site. Ch. Karnchang will be responsible for removing the excess concrete and soil inside the tunnel after the sealing process.

 

Structural experts have also weighed in on the broader implications. Professor Dr Amorn Pimanmas, President of the Thai Structural Engineers Association, examined the Samsen Police Station and confirmed that while its foundation piles have been damaged, the building remains stable. He emphasised two key factors affecting safety: further soil slippage and weather conditions. Rain could trigger additional soil movement, turning soil into a liquid state and potentially worsening structural damage.

 

Dr Pimanmas stressed that the police station’s stability must be reassessed daily. If there is no further soil slippage and weather conditions remain favourable, engineers believe the building could be reinforced despite the damage. However, authorities are monitoring the situation closely and preparing contingency plans should it be needed.

 

 

 

Key Takeaways

 

• Bangkok authorities altered repair plans to seal a tunnel collapse before heavy rain.

• Concrete pouring and sand filling will be used after slab-lifting attempts failed.

• Engineers stress ongoing daily assessments for the stability of nearby structures.

4 hours ago, thesetat said:

They are currently blaming shifting ground soil as the source of the sinkhole. However, I am curious about that being the real reasoning behind the sinkhole since there is currently underground construction being done right next to the sinkhole. 

 

That's not what I'm reading as the primary / original issue in the above news report:

 

"The sinkhole, measuring around 30 metres wide, 30 metres long and 50 metres deep, formed after a tunnel housing the Purple Line extension collapsed."
 

This sounds more like this is the underground version of the Rama II elevated expressway project that keeps dropping blocks of concrete onto passing vehicles below and killing people nearby.

 

It seems like the above reports are pretty typical about the way Thai media sources respond to these kinds of situations...

 

The coverage is all about the response to the issue and what various authorities are doing after the fact.

 

But not so much about what caused the mishap in the first place, because that would involve holding people / agencies responsible for what led to the original mishap occurring.

 

 

4 hours ago, thesetat said:

They are currently blaming shifting ground soil as the source of the sinkhole. However, I am curious about that being the real reasoning behind the sinkhole since there is currently underground construction being done right next to the sinkhole. 

You'd think the underground construction would have been impacted

2 hours ago, Georgealbert said:

 

Picture courtesy of Daily News

 

 

 

WOW!   That's a BIG mess, even by Bangkok construction standards!     

Sinkhole - that's my bank account right now 

20 hours ago, Georgealbert said:

Authorities have since deployed sandbags,

The trusted sandbags to the rescue, used during floods so why not give them a go in sink-holes.

One of the biggest holes I've ever seen in Bangkok.

2016 in Japan they had same size sink hole there was traffic back to normal 7 days later 

20 hours ago, Will B Good said:

Sandbags?

Yeah you got it right... maybe the heavy duty variety

16 hours ago, TallGuyJohninBKK said:

But not so much about what caused the mishap in the first place, because that would involve holding people / agencies responsible for what led to the original mishap occurring.

The one question that's been avoided is where did all the soil from the sink-hole go?

Off topic derogatory slur removed

21 hours ago, Will B Good said:

 

 

I wondered of there's been a massive unground water leak from this pipes that caused erosion.

I saw a report from a structural engineer on youtube and he reckon it was a burst water pipe that may have caused it. He also discovered that the underground station tunnel project was a joint venture Thai and Chinese with the latter being the main partner.You gotta wonder if it's the same company that was building the high rise building  that collapsed after the earthquake.

21 hours ago, Will B Good said:

Sandbags?

 

 

yep, sofar 50.000 of 'em! 🤪

The Italian Thai development company and their Chinese partners are not having much luck lately

1 hour ago, hotchilli said:

Yeah you got it right... maybe the heavy duty variety

Hope they are not biodegradable 

1 hour ago, hotchilli said:

The one question that's been avoided is where did all the soil from the sink-hole go?

From what I have seen, this was caused by water, probably from a burst main, that has liquified the soil. This has then somehow made its way into the underground station and then into the tunnels. This is where the soils has gone! 
Which means that the next question is, how did this all manage to get into this station and then into the tunnels? Another construction fault??

UPDATE
Engineers Propose Four Urgent Fixes for Bangkok Road Collapse

 

 

14 minutes ago, worrab said:

Which means that the next question is, how did this all manage to get into this station and then into the tunnels? Another construction fault??

And no-one asked... where's all this spoil coming from?

Look who was doing the construction again... Sino-Thai 

18 hours ago, Georgealbert said:

UPDATE
Concrete Plan to Seal Tunnel Before Rainfall

 

Picture courtesy of Daily News

 

Bangkok authorities have altered repair plans to urgently seal a collapsed tunnel entrance on Samsen Road, before heavy rainfall. The adjustment comes after attempts to lift concrete slabs failed, prompting a shift to pouring concrete and covering it with sand.

 

The change was confirmed on 25 September by Mr Suriyachai Rawiwan, Director of the Bangkok Metropolitan Administration’s Department of Disaster Prevention and Mitigation. The original plan, ordered by Governor Chadchart Sittipunt, involved using cranes and slings to lift concrete slabs. However, the slabs could not be lifted due to resistance from soil and structural debris within the tunnel. As a result, the Mass Rapid Transit Authority of Thailand (MRTA) and construction company Ch. Karnchang opted for an alternative method.

 

The revised plan involves pouring concrete directly to form a platform about three metres high to seal the tunnel entrance. Once set, sand will be packed over the concrete to reinforce the surface. This approach will also help support the structure of the nearby Samsen Police Station, which is adjacent to the collapse site. Ch. Karnchang will be responsible for removing the excess concrete and soil inside the tunnel after the sealing process.

 

Structural experts have also weighed in on the broader implications. Professor Dr Amorn Pimanmas, President of the Thai Structural Engineers Association, examined the Samsen Police Station and confirmed that while its foundation piles have been damaged, the building remains stable. He emphasised two key factors affecting safety: further soil slippage and weather conditions. Rain could trigger additional soil movement, turning soil into a liquid state and potentially worsening structural damage.

 

Dr Pimanmas stressed that the police station’s stability must be reassessed daily. If there is no further soil slippage and weather conditions remain favourable, engineers believe the building could be reinforced despite the damage. However, authorities are monitoring the situation closely and preparing contingency plans should it be needed.

 

 

 

Key Takeaways

 

• Bangkok authorities altered repair plans to seal a tunnel collapse before heavy rain.

• Concrete pouring and sand filling will be used after slab-lifting attempts failed.

• Engineers stress ongoing daily assessments for the stability of nearby structures.

Talk about pixxing in the wind...........

Wow... make a good math problem in engineering schools: just how many millions of sandbags would be required?

And remember, to fill that hole they will have to get sand/dirt/whatever equal in volume to that hole. 

1 hour ago, hotchilli said:

22 hours ago, Will B Good said:

Sandbags?

Yeah you got it right... maybe the heavy duty variety

 

Just spitballing here, but doesn't Thailand have mountains of trash laying around in dumps?

 

Properly handled, this could be a win-win.

 

19 hours ago, SAFETY FIRST said:

tunnel construction beneath is to blame 

Yes - "a tunnel housing the Purple Line extension collapsed."

That looks like a construction failure. Was the design flawed, ie., lacking subsoil analysis and adequate construction solutions and/or construction inspection?