I'm baking a cheesecake with pieces of pears, using rich shortcrust pastry. The problem is that, during the baking, the pear juice is soaking the pastry. How could I avoid that?
Whenever you're worried about something crisp being made soggy by something moist, the answer is usually fat. Brush the crust with butter or oil before you add the pears, and the oil will slow the absorption of water.
Alternately, dry out your pears. Cook them a bit. Roll them in sugar to dry them out some.
I'm surprised the pear juice is making it through the cheesecake batter. Usually that stuff keeps the liquids locked up tight. Maybe try a drier cheesecake, or one with a bit more egg?
Try baking the crust blind and then adding the fillings. This should ensure a crisp crust.
Coating fruit pieces in cornstarch, tapioca starch etc. can bind juices into a jelly around them instead of letting them seep into fillings; experimentation is needed to check whether it works well with your intended texture.