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I will add to what Uzair has said. For mass concrete, recommendations of ACI 207 are used to reduce heat of hydration during curing. This involves replacing cement with a recommended percentage of fly ash and water with crushed ice. The temperature inside foundation is monitored using thermocouples. Generally, contractor has to ensure that no part of concrete mass is allowed to become cooler than the hottest part by more than 20oC (68oF). Thanks.

There are two aspects of this question: a. When the concrete is to be placed in single layer, as in a tunnel construction (what IMO OP has asked for) Recommendations regarding maximum horizontal length of concrete pour for this case, are given in ACI Standard referred in my previous post. When the concrete is reinforced properly, to withstand applied loads as well as thermal cracking, next or adjacent layer of concrete may be cast both sooner (the same day) as well as later (e.g., next morning), depending upon availability of concreting party. Proper construction joint should however be provided at the face of concrete common between the two pours. When the the concrete is to be cast in panels, separated by expansion joints (as in the case of concrete pavements), casting is generally done in alternate panels at one time. b. When the Mass Concrete is to be laid in multiple-layers Guidance regarding Mass Concrete is given in ACI 207.1R-05. AFAIK, no specific time duration has been given by ACI for placement of successive layers in a mass concrete. However, last paragraph of ACI 309R-05 Section 7.2 provides general guidance in this regard, in following words: "When the placement consists of several layers, concrete delivery should be scheduled so that each layer is placed while the preceding one is still plastic to avoid cold joints. If the underlying layer has stiffened just beyond the point where it can be penetrated by the vibrator, bond can still be obtained by thoroughly and systematically vibrating the new concrete into contact with the previously placed concrete; however, an unavoidable layer line will show on the surface when the form is removed." Ways and means are available for execution of large mass concrete works in a single casting operation. Following link gives details of such a mass concreting job, involving casting of 5.5 m (18 ft) thick concrete slabs at 70 m (230 ft) depth belo ground level, carried in one-go using self-compacting concrete. http://www.silicafume.org/pdf/reprints-201407.pdf Regards.

1. According to ACI Concrete Terminology 2013, Mass Concrete is "any volume of concrete in which a combination of dimensions of the member being cast, the boundary conditions can lead to undesirable thermal stresses, cracking, deleterious chemical reactions, or reduction in the long-term strength as a result of elevated concrete temperature due to heat from hydration." Now, first of all it is necessary to check whether your concrete really comes under the definition of Mass Concrete or not. ACI 207.1R-05 does provide basic information & general guidance about mass concrete, but it does not specify any minimum dimensions of concrete to qualify as 'Mass Concrete'. Following links however suggest some critical dimensions of concrete to consider it 'mass concrete', as well as useful information regarding placement of mass concrete and recommended practice for effective control of heat of hydration & thermal cracking in mass concrete. a. https://www.concrete.org/tools/frequentlyaskedquestions.aspx?faqid=650 b. http://people.wallawalla.edu/~larry.aamodt/engr325/concrete_heating.pdf c. http://www.nrmca.org/aboutconcrete/cips/42p.pdf d. https://www.structurepoint.org/publication/pdf/pdh-Mass-Concrete-Structures.pdf e. ACI 301-05, Section 8 Mass Concrete (Includes required concrete placement temperatures, among others) f. http://people.ce.gatech.edu/~kk92/massconcrete.pdf g. http://www.agcia.org/documents/Mass Concrete Thermal Control.pdf In case your concrete tunnel lining actually falls within definition of Mass Concrete, you will need to adopt suitable measures (including installation of thermocouples, as advised above by Umar) to keep the concrete temperatures within limits recommended for mass concrete. 2. Alternately, you may ask your consultant to provide you the calculations to prove that concreting you are doing is mass concrete, and also to provide you the reference that requires waiting for 72 hours, to start the next pour. 3. You may possibly do such calculations yourself too, provided you have relevant temperature values and other required information. Guidance is available in following document:- http://www.oea.org.lb/Library/Files/Arabic/Downloads/Reports/ندوات ومؤتمرات/Presentation Mass Concrete OEA dec 20.pdf I don't have some reference now. However, if the tunnel lining concrete does not qualify for mass concrete, in the light of documents referred earlier, or (as already said earlier) the concrete reinforcement design & placement is adequate to counter both the applicable loads as well as thermal cracking, 72 hour restriction might not be applicable. In such a case, you can start next pour earlier. Regards.

Ofc SAFE strip forces will be different than those from manual method because of differences in strip widths. What is the strip width in SAFE vs in ACI or whatever method you are using? Also try changing slab from shell to membrane after you have done the above point.

You could use Limcon for steel connections.

In ETABS, SAFE, SAP axial forces are F11 and F22 in 1 and 2 directions resp. By default axis, a load applied in elevation to a wall will show axial force as F22. You can sumup/average total axial force by assigning it as a pier width of which depends on the length, spreadout and type of applied load. Axial capacity of wall as mentioned in above reply can be calculated like a column. You can calculate capacities of anything from PMM interaction (atleast for a beam, column and a wall). Just respect the boundary conditions.

Well thanks anyway. I can work with this much information so far. IA Regards,

Refer to "ACI 224.3R-95 Joints in Concrete Construction", Chapter 7 at the following link, for your required information:- http://xa.yimg.com/kq/groups/2173108/199513267/name/2243r_95.pdf Regards.