Discussion: View Thread

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose? 

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated. 

Thank you. 


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Kalyan,
  What does your economic analysis indicate?

------------------------------
James Justin Mercier, P.E., CFM
Life Member ASCE
Sr. Life Member IEEE
Austin Texas
512-442-4016
------------------------------

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Original Message------

Kalyan,
  What does your economic analysis indicate?

------------------------------
James Justin Mercier, P.E., CFM
Life Member ASCE
Sr. Life Member IEEE
Austin Texas
512-442-4016
------------------------------

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

You are correct that lift stations are to be avoided whenever possible.  You can expect extensive utility trench settlement with the first solution.  It is very difficult to achieve adequate compaction in such deep trenches.  The depths you are contemplating could well compromise the pavement structure.  However, I have recently dealt with that problem by using a geogrid (Triax 140 or 160), and 6-8 inches of flex base over the backfill.  We used good bedding material under and around the pipe but used the native soil (expansive clay) for the backfill compacted as well as possible.  Trench boxes were used for safety and to keep the trench as narrow as possible.  That really cuts down on cost as decent backfill is getting harder to find and more expensive in Texas.

------------------------------
James Anderson, MASCE
Principal
Anderson Consulting
North Richland Hills, TX
817-946-9943
James
------------------------------

Original Message:
Sent: 04-07-2019 18:26
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

Hi James,

At this point with lead times of different components with 12 lift stations makes it more difficult with respect to time and cost.

The first solution is cumbersome land requires more resources including backfill material . However all of it included equipment are locally available and can be done faster with right strategy in place . Barring 3-4 months of rains which is the same constraint for both the solutions

Regards,

Kalyan Emandi
+9689627765

Original Message------

Kalyan,
  What does your economic analysis indicate?

------------------------------
James Justin Mercier, P.E., CFM
Life Member ASCE
Sr. Life Member IEEE
Austin Texas
512-442-4016

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884
------------------------------

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC
------------------------------

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Original Message------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC
------------------------------

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

This should give you a bit more information.  One sack slurry, or flowable fill, or controlled low strength material (CLSM) can be used by adding cement to onsite soils, provided they have proper gradation, as indic dated in the cut sheet.  My experience is more in having the slurry delivered from a concrete supplier, who has a mix design in place for simply adding one sack of cement to sand, and adding water that allows the material to flow wherever you need it.  Hope this helps. 

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC
------------------------------

Original Message:
Sent: 04-11-2019 17:00
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We haven't considered one sack sand slurry. I will research it. If you can elaborate a bit more. It will be very helpful. Thank you! 

Original Message------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

I was not able to view the attchment, so I don't know if it addresses the issue of pipe floating when using flowable fill materials, but that is something you need to address. There are many different methods of securing pipe to hold it in place until the fill sets, but the uplift forces are signuficant so you must plan on some method of anchoring the pipe.

------------------------------
James Gernand EIT,A.M.ASCE
Redwood City CA
(650)544-0799
------------------------------

Original Message:
Sent: 04-11-2019 17:44
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

This should give you a bit more information.  One sack slurry, or flowable fill, or controlled low strength material (CLSM) can be used by adding cement to onsite soils, provided they have proper gradation, as indic dated in the cut sheet.  My experience is more in having the slurry delivered from a concrete supplier, who has a mix design in place for simply adding one sack of cement to sand, and adding water that allows the material to flow wherever you need it.  Hope this helps.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-11-2019 17:00
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We haven't considered one sack sand slurry. I will research it. If you can elaborate a bit more. It will be very helpful. Thank you! 

Original Message------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Since we're talking about stormwater pipe, I assume RCP is being used.  Unless the pipe is below groundwater level, hydraulic uplift isn't likely.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC
------------------------------

Original Message:
Sent: 04-12-2019 03:25
From: James Gernand
Subject: Drainage and Storm water Networks under Road Pavement

I was not able to view the attchment, so I don't know if it addresses the issue of pipe floating when using flowable fill materials, but that is something you need to address. There are many different methods of securing pipe to hold it in place until the fill sets, but the uplift forces are signuficant so you must plan on some method of anchoring the pipe.

------------------------------
James Gernand EIT,A.M.ASCE
Redwood City CA
(650)544-0799

Original Message:
Sent: 04-11-2019 17:44
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

This should give you a bit more information.  One sack slurry, or flowable fill, or controlled low strength material (CLSM) can be used by adding cement to onsite soils, provided they have proper gradation, as indic dated in the cut sheet.  My experience is more in having the slurry delivered from a concrete supplier, who has a mix design in place for simply adding one sack of cement to sand, and adding water that allows the material to flow wherever you need it.  Hope this helps.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-11-2019 17:00
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We haven't considered one sack sand slurry. I will research it. If you can elaborate a bit more. It will be very helpful. Thank you! 

Original Message------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

The pipe is below ground level. Twin walled HDPE pipe. Which is now being used quite frequently. Especially in Europe. 

The connections, pipe lifting and installation is much easier and faster than regular RCP .

------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Original Message:
Sent: 04-12-2019 10:09
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

Since we're talking about stormwater pipe, I assume RCP is being used.  Unless the pipe is below groundwater level, hydraulic uplift isn't likely.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-12-2019 03:25
From: James Gernand
Subject: Drainage and Storm water Networks under Road Pavement

I was not able to view the attchment, so I don't know if it addresses the issue of pipe floating when using flowable fill materials, but that is something you need to address. There are many different methods of securing pipe to hold it in place until the fill sets, but the uplift forces are signuficant so you must plan on some method of anchoring the pipe.

------------------------------
James Gernand EIT,A.M.ASCE
Redwood City CA
(650)544-0799

Original Message:
Sent: 04-11-2019 17:44
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

This should give you a bit more information.  One sack slurry, or flowable fill, or controlled low strength material (CLSM) can be used by adding cement to onsite soils, provided they have proper gradation, as indic dated in the cut sheet.  My experience is more in having the slurry delivered from a concrete supplier, who has a mix design in place for simply adding one sack of cement to sand, and adding water that allows the material to flow wherever you need it.  Hope this helps.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-11-2019 17:00
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We haven't considered one sack sand slurry. I will research it. If you can elaborate a bit more. It will be very helpful. Thank you! 

Original Message------

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Eric Sosnowski's suggestion regarding a flowable fill in the pipe area is a good one.  If you have access to an inexpensive supply of fly ash, the flowability can be improved without adding excessive water to the 1-sack mix.  You must be careful not to "float the pipe" while it is being applied.  The backfill will still be "diggable" even with the addition of Class C ash.  You may find it too expensive to use flowable fill for all the backfill.  That is why I suggested using geogrid and flexbase over the natural material in order to reduce stress on the pavement following trench settlement.

------------------------------
James Anderson, MASCE
Principal
Anderson Consulting
North Richland Hills, TX
817-946-9943
James
------------------------------

Original Message:
Sent: 04-11-2019 16:07
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Hi James, Thank you for the information. I am still looking into it. We do not have access to the material (fly-ash). Which in a sense kills the optimization of resources and time.

------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------

Original Message:
Sent: 04-12-2019 11:02
From: James Anderson
Subject: Drainage and Storm water Networks under Road Pavement

Eric Sosnowski's suggestion regarding a flowable fill in the pipe area is a good one.  If you have access to an inexpensive supply of fly ash, the flowability can be improved without adding excessive water to the 1-sack mix.  You must be careful not to "float the pipe" while it is being applied.  The backfill will still be "diggable" even with the addition of Class C ash.  You may find it too expensive to use flowable fill for all the backfill.  That is why I suggested using geogrid and flexbase over the natural material in order to reduce stress on the pavement following trench settlement.

------------------------------
James Anderson, MASCE
Principal
Anderson Consulting
North Richland Hills, TX
817-946-9943
James

Original Message:
Sent: 04-11-2019 16:07
From: Eric Sosnowski
Subject: Drainage and Storm water Networks under Road Pavement

My suggestion is that limiting the number of lift stations would be preferable, since you invite less long-term maintenance costs.  Have you considered using a one-sack sand slurry mix (at least to fill to a level of a couple of meters above the pipe) to avoid​ deter settlement issues? The material cost may be more, but you eliminate the need for compaction and testing in/around the pipe.  And the one-sack can be excavated with a backhoe if needed to access the pipe later.

------------------------------
Eric Sosnowski M.ASCE
Bluffton SC

Original Message:
Sent: 04-08-2019 08:10
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

With manholes every 40 meters tunneling seems out of question and more costly.

------------------------------
Kalyan Emandi
Sr.Project Engineer

Original Message:
Sent: 04-08-2019 06:10
From: Robert Arias
Subject: Drainage and Storm water Networks under Road Pavement

Did you consider tunneling?

------------------------------
Robert Arias M.ASCE
Arias and Associates Inc
San Antonio TX
(210) 308-5884

Original Message:
Sent: 04-06-2019 18:13
From: Kalyan Emandi
Subject: Drainage and Storm water Networks under Road Pavement

We are currently building a road network, the terrain is similar to Texas. i.e. Black Cotton Soil.

The current design depths of Foul Sewer Network at the deepest ins 10m. storm water is 6- 8 m deep with 3 Lift stations.

However, an alternative design limits the depth to a maximum of 4 meters but 12 Lift stations in order to save excavation.

What is the best option to choose?

I presume most of the countries are now moving away from lift stations and preferring deeper networks for long-term benefits.

If anyone has experienced this before or involved in these kind of projects at any level, your input is really appreciated.

Thank you.


------------------------------
Kalyan Emandi
Sr.Project Engineer
------------------------------