I am developing the wind loads on A-frame residential structure, dimensions 23'x25'x20' (Length x Width x Height). The project is located in North Carolina and the reference standard for wind load is ASCE 7-10. Although there is no a specific mention of A-frame structures in the standard, it...
Construction Dewatering and Groundwater Control, Powers, et al., 3rd Ed. lists a summary of analytical models for flow within an aquifer (Table 6.1 attached). I am trying to determine what the factor is that is applied to the basic equation for U.S. units. For example, for the radial flow...
I am trying to create a Mathcad worksheet to calculate the active and passive pressure coefficients using the method described in Bowles, Foundation Analysis and Design, 5th Ed. Specifically, there are 4 equations (pp. 609-611) given for the "passive log-sandwich mechanism" (see attached)...
Powers, et al., Construction Dewatering and Groundwater Control, Section 6.2, pp. 68-69, discusses radial flow to a well in a water table aquifer, which is the condition I am modeling. In Section 6.1 the equation for drawdown is presented for a confined aquifer; however, Section 6.2 states that...
I am working with a contractor to design a dewatering system for an open excavation 44 feet x 40 feet x 30 feet deep which will be shored on 3 sides with H-piles and timber lagging. The contractor has proposed a line of eductor well points behind the shoring and I am tasked with designing the...
I am having a contractor backfill an over-excavated spread footing with flowable fill. The volume required is less than a yard (27 cubic feet) so I am providing the contractor with a mix proportion by volume for the material. Several articles give the mix design based on weight, but the mix...
Thank you for the comments. I am trying to design the anchor bolt given a vendor supplied baseplate size and hole pattern. As I mentioned, the pump manufacturer has supplied maximum nozzle loads, which when applied simultaneously in all three directions, in combination with unbalanced rotor...
I am tasked with designing the anchorage for a vertical turbine pump at a water treatment plant. The guidance document for dynamic machine loads is ACI 351.3R-18, "Report on Foundations for Dynamic Equipment", which describes the calculation procedure for unbalanced loads. I also have the...
AISE Tech. Report No. 13, 2003, "Guide for the Design and Construction of Mill Buildings", references ASCE 7 for seismic design requirements. ASCE 7-10 (I'll have to update) Chapter 15, Table 15.4-2, Type: Inverted Pendulum, appears to be the appropriate structure type. The crane support...
Crane support structures are not specifically mentioned in the IBC Code (ASCE 7 by reference) for seismic design of building structures or non-building structures. The State of Illinois Engineering Code of Conduct lists the type of structures requiring an SE seal, which would appear to include...
I have set up a Mathcad Prime worksheet (PDF copy attached) which solves for the required depth of embedment, D, for the lateral earth pressure shown in Figure 3.11.5.6-5, AASHTO 2010 LRFD Bridge Design Specifications. The retained soil and embedment soil are both cohesive. The worksheet...
I am developing a MathCAD worksheet to provide a design check for temporary shoring using soldier piles and timber lagging. I have a copy of AASHTO 2010 and would like to develop the solution for the configuration shown in Figure 3.11.5.6-2, which is for a discrete vertical wall element...
Thank you for the responses. I have attached Figure 3.11.5.6-2 which shows the forces acting on the vertical element embedded in rock, which in this case is an HP pile supporting timber lagging. The force acting on the rock socket is directly related to the shear strength of the rock, Sm in...
I am trying to calculate the required depth of embedment, D for a rock-socketed HP pile for a non-gravity cantilevered wall according to 2010 AASHTO LRFD Bridge Design Specifications. Specifically, I am using timber lagging spanning 6-8 feet between HP piles set in concrete filled 2'-6"...
Thank you all for a good discussion. I have always felt that more information will help clarify a problem and work towards a successful solution. I will respond in outline form to some of the comments/suggestions.
1. The railcars are used in a battery recycling center and hold two (2)...
Thank you for the response. I have since found several sources that discuss rail car wheel to rail friction and the consensus seems to be that the rolling resistance of the stationary car is 2 - 2.5 times that of the cars in motion. The value calculated in this way is orders of magnitude less...
I am modeling a capstan (winch) equipment support that pulls three (3) rail cars with a wheel load of 22.5 kips each. Assuming the first two cars are in motion, rolling friction applies to the eight (8) wheels (4 per car) of the first two cars and static friction applies to the four (4) wheels...
Thank you for the response. I am using RISA-3D for the analysis and it has a moving loads analysis tool, which I am using for the load combinations referenced in the ASCE Guide. There seems to be a lot of room for "engineering judgement" as to which load combinations are applicable. I have...
I am currently developing an analysis model for a 5T top running single girder, pendant operated crane in an existing structure. The owner has decided to support the 3-bay free standing structure on drilled shafts to allow the structure to be located up against the wall. For developing loads...
