Compose cross-section data model

Function ready condition: - if all input tables are empty in case of no soil model (function has to be processed also in case of no soil) - if SOILNB and SUPANG are tested in case of soil model TOPLOAD, LAMBDA and SOILSUP may remain empty (means values=0.), but have to be tested when containing data.

Function error condition: 7 error conditions, 22 warning conditions, 10 messages

Defunct.

Defunct.

Ovalisation > 25 % of diameter

An element ovalisation after redistribution exceeds 25% of DIAM.

(For the elements in question the fields of OVAL4-O in table W-REDIS are made red. It's not possible to make further (stress) calculations because of the instability of the cross-section.)

External pressure > critical one

The external pressure is greater than the critical one.

(The influence of soil pressure (SOILNB, TOPLOAD, LAMBDA, SOILSUP) is included.)

Bend parameter < 0.01

The bend parameter Lambda during calculations with Section Model option Ovalising or Material Model Non-Linear becomes less than 0.01.

(The bend parameter value should not be less than 0.01, because the modeling of the bend behaviour becomes too inaccurate.)

Will not calc. Supports & Oval. Redist.

The combination of supports being present in the pipe configuration and the ovalisation redistribution model option set to ‘none’ is not advisable. This error indicates that as a response to the question “Supports and no oval. redistribution is not advisable. Stop calculations?” the user chose to stop the calculations.

(To continue, set back design function 1, set the ovalisation redistribution model option to ‘allowed’ and recalculate the project..)

Diam/wallth ratio < 5, can't calc. DF6.1

Extreme diameter/wall thickness ratio occurs, the D/t ratio is smaller than 5.

(See table 'Pipe dimension data' [PIPEDIM] in design function 3.1. The current design function can only be calculated with ratios of 5 and larger)

Model singularity found when calc.

The pipeline is modeled in such a way that singularity occurs.

One of the possible causes is a very short element next to an element with a normal length.

(See table 'Elements of pipeline' [ELEMNTS] in design function 2 and reconsider the pipeline model.

Cross-section data ignored

There is no soil at all and one or more of the input tables SOILNB, TOPLOAD, LAMBDA, SUPANG and SOILSUP contain data.

•output table CROSDAT will be filled with zero values.

Soilnb greater than rvt

At one or both nodes of an element a SOIL model (values ≠ 0.) has been specified and the specified SOILNB value is greater than the average RVT value at the nodes.

General loadfactor ≠ 1

The general load factor in table LOCASE unequals 1.

(The specified top(soil)loads SOILNB and TOPLOAD are multiplied with the general load factor. The warning is given because this may be not intended (especially in case of NEN3650 calculations).)

Ovalisation is 'value' % of diameter

The ovalisation of an element exceeds 10% of diameter.

Diameter ratio < 90 % at redistribution

The redistribution key is active and in the pipeline a transition in element diameter with a ratio of less than 0.9 occurs.

(The redistribution calculation model is less realistic in case the diameters of two adjacent elements differ more than 10 %.)

Topload not placed after infin node

The redistribution key is active and a TOPLOAD has been specified at an INFIN boundary point and beyond.

(Topload is applied on the pipeline considered only. Redistribution is correct but the influence on the INFIN part is not calculated.)

Redistribution without soil not done

The redistribution key is active and there is no soil.

(Redistribution involves redistribution of (peak) soil loadings and as a result deformations of the cross-sections along the pipeline.)

Closed end assumed to be rigid at redis

The redistribution key is active and a closed boundary point exists in the configuration.

(For the redistribution of cross-sectional deformations along the pipeline it is assumed that a CLOSED end/boundary point is rigid with regard to the adjacent sections. This means that with a closed end the pipe will remain circular and the redistribution will be damped.)

Moment ADDCROS > 25 % of INTFOR

The additional bending moment calculated and reported in table ADDCROS exceeds 25 % of the bending moment from table INTFOR.

(The maximum value of the moment in table ADDCROS (always in a vertical plane) has been compared with the maximum value of M-BEN in table INTFOR (may be in any plane). This warning has been given for information only.)

'title' at slack element (number1 - number2)

At elements with SLACK a top (soil) load or a horizontal soil support has been specified.

number1 / number2 = first/last slack element with (top) soil load.

('title' is either SOILNB or TOPLOAD or LAMBDA or SOILSUP. If one of these loads is specified, the load is applied on the cross-section. Especially in combination with Loading Redistribution applied the results may be not in accordance with the existing situation.)

Iteration stopped (DIF/BEL 'value')

As a result of additional cross-sectional loads from ADDCROS the iteration process checking for gaps has reached the max. number of 100. The value reported is the disequilibrium divided by the load.

Ext. press + soil elem 'number' 'value' % of crit

The external pressure is greater than 50 % of the critical one for radial elastic instability.

'number' | = element number with maximum external pressure |

'value' | > 50 |

(The influence of the soil is taken into account.)

El 'num1' - 'num2' ext. press > 33 % of crit

The external pressure is greater than 33 % of the critical one for radial elastic instability.

'num1' | = first element number of series |

'num2' | = last element number of series |

(The influence of soil pressure is included.)

Allow. impl. press exceeded ('num1'/'num2')

The external pressure exceeds the critical explosion pressure divided by the safety factors according to NEN 3650-2:2017.

'num1' | = first element number encountered |

'num2' | = last element number encountered |

(It concerns generally not all elements between 'num1' and 'num2'.)

Allow. impl. mom. exceeded ('num1'/'num2')

The bending moment exceeds the critical explosion moment divided by the safety factors according to NEN 3650-2:2017.

'num1' | = first element number encountered |

'num2' | = last element number encountered |

(It concerns generally not all elements between 'num1' and 'num2'.)

'value' % of allowable impl. pressure ('num')

The external pressure exceeds 100 % of the allowable pressure with reference to implosion of the pipe cross-section.

'value' contains the highest value found

'num' = element with highest value

'value' % of allowable impl. moment ('num')

The bending moment exceeds 100 % of the allowable bending moment with reference to implosion of the pipe cross-section.

'value' contains the highest value found

'num' = element with highest value

(NEN 3650-2:2017, appendix D.3.3.5, provides 2 formulae for calculating the allowable bending moment due to implosion: one for a loading case with bending moment only and one for a combination of external pressure and bending moment.)

ADDCROS iteration >100 diseq 'value'

The calculation of data of the ADDCROS table was halted after 100 iterations. No equilibrium has been found.

'value' shows the relative disequilibrium (DISEQ/LOAD)

Table CROSDAT, RVSOCC 'value' %

In table CROSDAT, a calculated rate of soil bearing capacity under the occurring soil loads and soil reactions (RVSOCC1 or RVSOCC2) greater than 120% has been found.

'value' shows the maximum percentage found.

'value' shows the relative disequilibrium (DISEQ/LOAD)

Supports present, but no Oval. Redist.

The combination of supports being present in the pipe configuration and the ovalisation redistribution model option set to ‘none’ is not advisable. This warning indicates that as a response to the question “Supports and no oval. redistribution is not advisable. Stop calculations?” the user chose to continue with the calculations.

(Unrealistic high ovalisation values at the support location(s) is a consequence of this choice. For more realistic results, set back design function 1, set the ovalisation redistribution model option to ‘allowed’ and recalculate the project.)

Joint at 'num' leaking (SoilNB)

A joint without stop has a rotation beyond the maximum allowable rotation. In design function 5 this maximum was not reached, but as a result of the extra SoilNB it is reached now. When more than 2 joints leak only the first and last leaking joints are reported in two separate warnings . The total number of leaking joints are reported in M610/9.

'num' = node of leaking joint

(When the joint does not leak as a result of the extra SoilNB but does leak when also extra topload is applied (SoilNB+Topload) is reported.) ¹

Joint at 'num' at stop (SoilNB)

A joint with clearance has reached the maximum allowable clearance (either in case of compression or tension). In design function 5 this maximum was not reached, but as a result of the extra SoilNB it is reached now. When more than 2 joints stop only the first and last joints without any clearance left are reported in two separate warnings . The total number of 'stopping' joints are reported in M610/10.

'num' = node of joint without any clearance left

(When the joint does not 'stop' as a result of the extra SoilNB but does 'stop' when also extra topload is applied (SoilNB+Topload) is reported.) ¹

'title' in CROSDAT set to no soil

A soil parameter has been specified at a pipe section without soil.

(title = soil load parameter SOILNB or TOPLOAD The presence of soil is governed by the specification of RVS. For pipeline sections without soil load parameters are ignored.)

Zero displ. with redistribution

All displacements resulting from Design function 5 are zero and the Ovalisation Redistribution option in function 1 has been set to Allowed.

(Redistribution is useless in this case.)

'value' % of allowable implosion pressure

The external pressure exceeds 75 % of the allowable pressure with reference to implosion of the pipe cross-section.

('value' contains the highest value found.)

'value' % of allowable implosion moment

The bending moment exceeds 75 % of the allowable bending moment with reference to implosion of the pipe cross-section.

('value' contains the highest value found.)

Disequ. in ADDCROS : ‘value1’/’value2’

A disequilibrium between loading and reaction has been found in the data of table ‘Additional cross-sectional loads’ [ADDCROS]. The maximum is reported, with ‘value1’ the loading and ‘value2’ the reaction.

(This message is only generated if the disequilibrium is > 1%)

ADDCROS ‘nm’ elm w gap (‘numb1’-‘numb2’)

While calculating data for table ‘Additional cross-sectional loads’ [ADDCROS], ‘nm’ elements were detected that keep changing state from “no gap between element and soil” to “gap between element and soil”. In order to finish calculations, these elements were ultimately calculated as having a gap between element and soil (worst case). All ‘nm’ elements are located between element number ‘numb1’ and element number ‘numb2’

ADDCROS iterat changed, affects ‘nm’ elm

A total of ‘nm’ elements were calculated using an incorrect soil stiffness (KLS instead of KLT or vice versa). In order to finish calculations, this situation was only corrected for some of those elements. Using this approach a solution was found, indicating that the influence of the incorrect soil stiffness with the rest of the elements is negligible.

(This message is only generated after more than 100 iterations.)

'num' joints leaking (SoilNB)

When more than 2 joints leak the total number of leaking joints as reported in W610/21 including the ones warned for.

'num' = number of leaking joints

(When the joints do not leak as a result of the extra SoilNB but do leak when also extra topload is applied (SoilNB+Topload) is reported.) ¹

'num' joints at stop (SoilNB)

When more than 2 joints stop the total number of 'stopping' joints as reported in W610/22 including the ones warned for.

'num' = number of joints without any clearance left

(When the joints do not 'stop' as a result of the extra SoilNB but do 'stop' when also extra topload is applied (SoilNB+Topload) is reported.) ¹

¹ : Two checks are performed, one with only SoilNB, and one with SoilNB+Topload. When a joint leaks or stops as a result of only SoilNB it is reported. When additional Topload is applied the joint is reported again. This counts for warnings W610/21 and W610/22 as well as for M610/9 and M610/10. So, having 5 leaking joints and 3 of them leak due to only SoilNB and also Topload is applied, the messages 'M610/9 3 joints leaking (soilnb)' and 'M610/9 5 joints leaking (soilnb+topload)' are reported

H6104, last changed: 11/4/2020

See also: