Gravid females

[jandh]

Hi I have to girls that have been digging on and off for a week ,one has been mounting the other girls inbetween digging .the trouble is they are digging on the lawn and not getting any where as the soil is rock hard clay .I've made a make shift small area for them , and 3 of my tortoises have layed there in last few weeks , I've put some of the grass that they have been scrapping away on too of my nest site to encourage them and I have poured hot water there also .any tips on what I can do please.